Following the discovery of America, Spain embarked upon a program of exploration, conquest, and exploitation of the lands which had been awarded to her by Pope Alexander VI. In 1513 Ponce de Leon explored Florida, and Hernando Cortes conquered Mexico six years later. Texas and the Southwest were first explored in 1528 by Alvar Nunez Cabeza de Vaca, who returned to Mexico with the story of the fabulous seven cities of Cebola. This created a great deal of excitement, and a number of reconnaissance expeditions set out to explore the arid Southwest. The most important was that of Francisco Coronado, who traversed most of the southwestern portion of the present United States searching in vain for these elusive cities. The Mississippi was discovered and partially explored by Hernando de Soto in l541
The first Spanish colony within the present limits of the United States was founded by Menendez de Aviles in 1565 at St. Augustine, Florida. The Province of Florida was created shortly thereafter and covered all the land west to Mexico. Spain retained possession of Florida until February 10, 1763, when it was ceded to Great Britain under the Treaty of Paris. Article 6 of this treaty fixed the boundary between Florida and Louisiana as a line drawn down the middle of the Mississippi to the Iberville River; thence down the middle of the Iberville River through Lakes Maurepas and Pontchartrain to the Gulf. Great Britain divided Florida into two areas. The portion west of the Apalachicola River was, known as West Florida, and the land east thereof was referred to as East Florida. In 1781 Spain invaded and captured West Florida. Two years later, title to both East and West Florida reverted to Spain under the Treaty of Parisof September 3, 1783. A dispute arose between the United States and Spain over the northern boundary of Florida, and by the Treaty of October 27, 1795, it was agreed that their common boundary was the 31ºof north latitude. Due to a fear that France might seize West Florida, the area west of the Pearl River was annexed to the United States in 1812. As a result of Spain's inciting the Seminole Indians to raid into Georgia, General Andrew Jackson invaded East Florida and captured Pensacola. Following the end of these hostilities, Spain, by the Treaty of February 22, 1819, ceded its title to the 37.9 mi11ion acres of land contained in East and West Florida to the United States for five million dollars.
The French engaged in settling Louisiana following its discovery by LaSalle. In 1699, Governor Pierre le Mayne d’Iberville established settlements at Biloxi and on Dauphin Island. Twenty-three years later New Orleans was founded on the bank of the Mississippi, and it became the capital of the province, which was bounded on the north by Illinois and the Missouri River; on the east by the Carolinas and the Perdido River; on the south by the Gulf; and on the west by New Mexico. This covered the entire area drained by the Mississippi and its tributaries, including a large part of Texas.
Spain assisted France in the French and Indian War.' As a result of their defeat England in the Treaty of Paristook Canada and all the area west of the Mississippi and north of the thirty-first parallel from France and also Florida from Spain.
In order to compensate Spain for the loss of Florida, France secretly ceded the island of Orleans and all of Louisiana west of the Mississippi to Spain under the Treaty of Fontainbleau of November 3, 1762. Spain did not physically take over the administration of Louisiana until the arrival of Governor Alexander O'Reilly on July 24, 1769. At first he continued the French system relating to land grants, but after an inspection of parts of the territory he issued a Proclamationon February 18, 1770 in which he stated:
All grants shall be made in the name of the king, by the Governor General of the Province, who will, at the same time appoint a surveyor to fix the bounds thereof, both in front and in depth, in the presence of the ordinary judge of the district and of the two adjoining settlers, who shall be present at the survey....
Spain retroceded Louisiana to France by the Treaty of San Ildefonsodated October I, 1800. France, in turn, sold the 756,961,280 acre tract to the United States for $15,000,000 plus the assumption of claims totaling $3,738,268.98 due the citizens of the United States by the Treaty of Parisdated April 30, 1803. By virtue of this treaty, the United States also claimed the area between the Iberville and Perdido Rivers. The southwestern boundary of the Louisiana Purchase, which was also the international boundary between the United States and Spain, was defined in the Treaty of February 22, 1819, as being a line beginning on the Gulf of Mexico at the mouth of the Sabine River and running:
. . .north, along the western bank of the Sabine River, to the 32d degree of Latitude; thence, by a line due North to the degree of Latitude where it strikes the Rio Roxo of Natchitoches, or Red River; then, following the course of the Rio Roxo westward, to the degree of Longitude 100 West from London, and 23 from Washington; then, crossing the said Red River, and running thence by a Line due North to the River Arkansas; thence, following the course of the Southern bank of the Arkansas, to its source, in Latitude 42 North; and thence, by that parallel of Latitude, to the South Sea. The whole being as laid down in Melish's Map of the United States, published at Philadelphia, improved to the first of January, 1818. But, if the source of the Arkansas River shall be found to fall North or South of Latitude 42, then the Line shall run from the said Source due South or North, as the case may be, till it meets the said Parallel of Latitude 42; and thence along said Parallel to the South Sea.
Spain expressly relinquished all of its claims to lands lying north and east of this line. Mexico recognized this ·boundary in the Treaty of January 12, 1828. Thus, the indefinite northern boundaries of the Spanish and Mexican frontier provinces finally were fixed.
Spain laid claim to Texas as a result of Alonso Alvarez de Pineda's having sailed along and mapped its coast in 1519. As a result of this expedition, Governor Francisco de Garay of Jamaica made an unsuccessful attempt to colonize Texas. Only after being frightened by LaSalle's landing at Matagorda Bay in 1685 did Spain seriously undertake the settlement of Texas. After making several exploratory expeditions into the area, Alonso de Leon, Governor of the Province of Coahuila, established the mission of San Francisco de Tejas on the Neches River in 1690 to Christianize the Tejas Indians. Discouraged by the shortage of supplies and threats from the Indians, the friars burned the mission and abandoned the project on October 25, 1693.
No further steps were taken by the Spaniards to exert jurisdiction over Texas until a group of French traders from Louisiana under the leadership of Louis de St. Denis made a trip through East Texas to the Rio Grande and aroused their suspicions that France was on the verge of seizing the territory. In March, 1716, Domingo Ramon established a chain of missions for the conversion of the Indians, and a presidio for the protection of the missions. This line of settlements extended from Nacogdoches, Texas, to Robeline, Louisiana. He also settled a total of forty civilians near the missions and staffed them with twelve missionaries. The presidio was given a complement of twenty-five soldiers. In 1718 it was decided to establish another colony halfway between the East Texas missions and the Rio Grande at a site on the San Antonio River. Thus, San Antonio de Bexar was founded with ten families. Texas was established as a separate Spanish province in 1727, but the boundaries were not defined. There was some colonization during the next sixty years. However, most of the projects failed and were abandoned. Thus, when Mexico gained its independence in 1821, there were only three towns within Texas --Nacodoches, La Bahia (Goliad), and San Antonio.
Prior to 1805, Texas' southern boundary was considered to be located along the Medina-San Antonio River system, thereby forming the northern boundary of the Provinces of Nuevo Santander and Coahuila. However, in 1805, a Royal Cedula was issued which described Texas' boundaries as follows:
Beginning at the mouth of the Nueces River; thence up that river to its junction with Moro Creek; thence in a northerly direction to near the Garza crossing of the Medina River; thence up that river to its source; thence in a direct line to the source of the San Saba. River; thence northwesterly to the intersection of the 103rd meridian west longitude and the 32d parallel of north latitude; thence northeasterly to the intersection of the Red River by the 100th meridian; thence down said river.
An Order of 1811 and an official map of 1816 also fixed the southern boundary between Texas and the Nuevo Santander at the Nueces and the Medina as the common boundary between Texas and Coahuila. While Nueva Vizcaya adjoined Texas -on the southwest and New Mexico was located immediately west of Texas, the settlements in these provinces were so widely separated and the arid prairie lands between the settlements were of so little value that there was little need to define their respective common boundaries precisely. There was only one dispute between Texas and its western neighbors involving the area west of San Antonio. This question over whether the presidio at San Saba should be under the jurisdiction of Texas or New Mexico. In 1765 the matter was resolved in Texas’ favor.
Texas, following the reorganization of the Mexican government under the Constitution of 1824, was made a department and was combined with Coahuila in order to form the single state of Coahuila-Texas. The Constitution made no reference to boundaries of Coahuila-Texas; and, therefore, it is presumed that the former boundaries of Texas were still applicable to the northern portion of the new state. Under this Constitution, Mexico invited foreigners to immigrate to Texas and offered liberal land grants under both national and state colonization laws as a special inducement to encourage such immigration. These colonization laws caused great numbers of settlers to rush to Texas, primarily from the United States. For the most part, these pioneers were a rugged, industrious type of family men who wanted land to establish homes, and not merely adventurers and speculators. This rapid influx of freedom-loving Anglos, which increased the population of Texas from 3,000 in 1821 to from 35,000 to 50,000 in 1836, greatly alarmed the Mexican government and resulted in the passage of the Act of April 6, 1830, which barred further immigration from the United states. While this law hastened the inevitable Texas Revolution, its immediate cause was the Mexican government's refusal to grant the Texans' request for separate statehood and the issuance of an order reducing the size of the Texas militia and disarming its citizens. Actual hostilities broke out in October, 1835, and on March 2, 1836, a convention of delegates declared Texas to be independent of Mexican control. Success at the Battle of San Jacinto made Texas an independent nation in fact on April 21, 1836. President Santa Ana of Mexico, while a prisoner of war, signed the Treaty of Velasco, recognizing Texas' independence and agreeing to withdraw the Mexican troops to the other side of the Rio Grande. A secret agreement was also signed calling for a "treaty of commerce, amity, and limits" in which the boundary between Texas and Mexico was to be established in a manner that Texas would not extend beyond the Rio Grande. Once Santa Ana was freed and he and his troops were safely back in Mexico, the Mexican government repudiated the treaty and secret agreement and refused to enter into further peace negotiations. Notwithstanding the fact that the Treaty of Velasco had failed to define the Texas-Mexico boundary precisely, it served as a basis for Texas' claim to portions of Tamaulipas, Coahuila, Chihuahua, and New Mexico. On December 19, 1836, Texas passed an act in which it reduced its claim to writing and defined its boundaries as follows:
Beginning at the mouth of the Sabine River and running west along the Gulf of Mexico three leagues from land, to the mouth of the Rio Grande; thence up the principal stream of said river to its source; thence due north to the forty-second degree of latitude; thence along the boundary line as defined in the treaty between the United States and Spain to the beginning.
These boundaries embrace a total area of 242,594,560 acres of land.
On January 25, 1845 the House passed a resolution inviting Texas to join the Union as a state. The Republic of Texas accepted and on December 25, 1845 was admitted into the Union. Thus Texas, inclusive of all the territory claimed by the Republic became a part of the United States.
Following the annexation of Texas into the Union, Federal and Mexican troops clashed when General Zachary Taylor, on April 5, 1846, attempted to occupy the area between the Nueces and Rio Grande Rivers and precipitated the Mexican War. Less than three weeks later, President James K. Polk signed a Congressional resolution declaring war on Mexico on the ground that she had crossed the southern boundary of the United States and "shed American blood upon American soil.”  Hostilities ceased on February 2, 1848 with the signing of the Treaty of Guadalupe Hidalgo. Under this treaty, Mexico relinquished all of its rights in the area north of the Rio Grande to the United States. Thus, it appeared that Texas' de facto claim to the disputed area had been perfected. However, the Territory of New Mexico, which had been created by General Stephen Watts Kearney following his bloodless conquest of New Mexico in 1846, vigorously protested Texas' claim to the area located east of the Rio Grande, over which New Mexico had exercised jurisdiction for more than a century prior to the founding of the Province of Texas. Texas' claim was especially distasteful to the New Mexicans since it embraced their ancient capital, Santa Fe. The controversy soon developed into a serious North-South sectional issue, which was finally settled as a part of the Compromise of 1850. Under the Act of September 9, 1850, the United States offered to purchase the disputed area from Texas for ten million dollars. Texas accepted the offer on November 25, 1850. Thus, the approximately 67 million acres located north and west of the following line was awarded to New Mexico:
Commence at the point at which the meridian of one hundred degrees west from Greenwich is intersected by the parallel of thirty-six degrees thirty minutes north latitude; thence due south to the thirty-second degree of north latitude; thence west along said parallel to the Rio Grande.
Spain claimed what is now the southwestern portion of the present United States by virtue of the discoveries of Christopher Columbus and the conquests of Cortez, De Soto, Coronado and Espejo. The missionaries followed close upon their heels and they, in turn, were followed by successive groups of colonists who gradually appropriated and developed the area. In 1561, Francisco de Ilarra was commissioned by Viceroy Luis de Velasco to conquer and rule the northern region of New Spain. He established the Province of Nueva Vizcaya with Durango as its capital. It covered the territory lying north of the Province of Zacatecas and included all of the modern Mexican States of Durango, Chihuahua, and Sonora, together with portions of the States of Coahuila and Sinaloa. 
Juan de Onate was awarded a contract in 1595 for the conquest and colonization of New Mexico. He took formal possession of the area on April 30, 1598, at a point on the Rio Grande about 25 miles south of El Paso del Norte. The first permanent settlement in New Mexico was established at Santa Fe in 1609. While the founding of the Province of New Mexico cut off the indefinite northern jurisdiction of the Province of Nueva Vizcaya, specific boundaries were not prescribed in Onate's contract. However, at that time it was generally understood and accepted that New Mexico extended from the Pacific Ocean on the west to the Atlantic on the east. Its northern limits were recognized as being the ones which the hostile Indians would force the colonists to accept, and its southern boundary was considered as beginning where Nueva Vizcaya stopped. Since the settlements in Nueva Vizcaya and New Mexico were separated by a six-hundred mile, uninhabited gap, there was no need for a precise boundary between the two provinces.
In order for the isolated New Mexican settlements to survive, communication along the Camino Real had to be maintained. Therefore, New Mexico in 1659 established the town of El Paso del Norte at the strategic southern pass through the continental divide. It soon became the midway rest stop on the long weary stretch between Santa Fe and Chihuahua. When the Pueblo Indians revolted and forced the Spaniards to retreat from the upper Rio Grande Valley in 1680, El Paso del Norte became the capital of New Mexico. This precipitated a dispute between New Mexico and Nueva Vizcaya and, on November 28, 1684, New Mexico's jurisdiction over the area between the Rio Grande and Sacramento Rivers was affirmed by the Viceroy. Twelve years after the outbreak of the Pueblo Revolt, Diego de Vargas reconquered New Mexico.
About this same time the French commenced encroaching upon the northeastern frontier of New Spain and caused the Viceroy to create the Province of Coahuila in 1686. This province covered the portion of Nueva Vizcaya lying north of latitude 26° between the Bolson de Mapimi and the Rio Grande.
Meanwhile, the Jesuits were engaged in a program of Christianizing the Indians along the Gulf of California. Gradually they extended their efforts westward. On March 15, 1687 Father Eusebio Francisco Kino founded the mission called Nuestra Senora de los Dolores on the San Miguel River. Kino first entered what is now Arizona in 1691. He found the prospects for missionary work in the Santa Cruz Valley, which he called Pimeria Alta, to be good. However, a revolt of the Pimas in Sonora prevented the establishment of missions in the area for nearly a decade. On April 28, 1700 he laid the foundations for the Mission of San Xavier del Bac. Additional missions and visitas were constructed between 1700 and 1711. By Royal Cedula dated March 11, 1732, the Provinces of Sonora and Sinaloa were created out of the portion of Nueva Vizcaya lying between the continental divide and the Gulf of California. 
Threatening advances made by the British and Russians along the northern Pacific coast prompted Spain to take affirmative action in 1767 to insure its control over California. Colonization expeditions were sent into the area and by the end of 1776 Spain had pushed its frontier northward more than eight hundred miles and established a chain of presidios and missions extending up the coast from San Diego to San Francisco. Meanwhile, a division of Alta and Baja, California, had been ordered by Royal Cedula dated April 8, 1770. Two years later a concordato was signed fixing the division line at a point about fifteen leagues south of San Diego. Governor Felipe de Neve moved to California in February, 1777, established his capital at Monterrey, and commenced the development of the new Spanish province.
The Royal Cedula of August 22, 1776, reorganized the Spanish Colonial government by removing the northern provinces of New Spain from the Viceroy's jurisdiction. As a result of this decree, the provinces of Sonora, Sinaloa, Upper California, Lower California, Coahuila, Nueva Vizcaya, Texas and New Mexico were combined into the Provincia Internas. This consolidation had little effect on the provinces and, for all practical purposes, it merely set up a new Viceroyalty of sorts. The provincial governors were deprived of their military jurisdiction, which was placed in the Commandant-General of the Provincia Internas. They also reported to the Commandant-General on other matters instead the Viceroy. Thus, in addition to military responsibilities, the Commandant-General had considerable influence over the Judiciary, Clergy, and Treasury. The immense size of the Provincias Internas rendered it difficult to defend and govern. Therefore, in 1786, it was divided into two military districts. These districts, in turn, were subdivided into twelve intendencias and three provinces. The intendencias and provinces were grouped into two divisions known as the Provincias Internas de Oriento and Provincias Internas de Occidento. On November 23, 1792, the two divisions were reunited after detaching the California, Nuevo Leon, and Nuevo Santander. Thus, the Provincias Internas was composed of the Provinces of New Mexico, Nueva Vizcaya, Texas, Coahuila, Sonora and Sinaloa. The same objections which led to the splitting of the Provincias Internas in 1786 forced its division into two separate jurisdictions in 1804. Once again they were called Eastern and Western Interior Provinces. To determine the boundary between the two divisions, the Commandant-General of the Eastern Interior Provinces ordered Brigadier Joaquin de Arrendondo to survey the boundary between Nueva Vizcaya and Coahila in 1815. The survey of this line commenced at the point where the Sierra Reimundo abuts the Rio Agua Naval; thence north along the mountains to the Presidio de Mapini; thence in a northeasterly direction through the Laguna de Tlahualila and Laguna de Jaco to the point where the 106th parallel intersects the Rio Grande near the old Presidio de San Vincenti; and thence in an easterly direction to the head waters of the Medino River and the western boundary of Texas.
The selfish and oppressive measures of Spain led to constant and ever increasing discontent in Mexico, which finally culminated in open rebellion. On February 24, 1821, Augustine Iturbide proclaimed the independence of Mexico at the small town of Iguala. When the revolutionary army captured Mexico City on September 27, 1821, the Spanish regime fell. An Empire was founded on May 18, 1822 with Iturbide as Emperor. However, he was not given absolute power and ruled in conjunction with a National Congress composed of two chambers. A number of the Congressmen opposed the Empire and sought to replace it with a Federal Republic. After a brief and frenzied reign the Empire was overthrown on March 8, 1823 and Iturbide was executed a year later.
Once the Empire had been abolished, the National Congress called a Constituent Congress to write a Constitution and named a military triumvirate to perform the executive functions until a new government could be established. The Constituent Congress drafted a Republican Constitution patterned upon the Constitution of the United States. The Republic of Mexico was created on October 4, 1824, with the adoption of this constitution. The union consisted of eighteen states and three territories. 
In the meantime, the old Spanish Province of Nueva Vizcaya had been divided into the provinces of Chihuahua and Durango. By an act dated July 27, 1824, the National Congress described Chihuahua as covering all of the territory lying between a straight line drawn from east to west at the Town of El Paso del Norte, with the jurisdiction it had always possessed, and a straight line drawn from east to west at the Hacienda de Rio Florida and its jurisdiction. On December 27, 1825, Chihuahua adopted a state constitution, which provided that the boundaries of the state should correspond with those prescribed by the Act of July 27, 1824. Since El Paso del Norte had claimed jurisdiction over the area lying south of the Jornada del Muerto, Chihuahua, in its Colonization Law of 42 May 25, 1825, authorized the colonization of the lands at El Bracito and the "upper part of the Rio del Norte, as far as the lands belonging to the jurisdiction of El Paso and of which use has been and is made, and where the boundary line ought to be described, and the boundaries with the territory of New Mexico."
In order to obtain specific and reliable information concerning its lands, the State of Chihuahua passed an act on October 22, 1833, creating a Geographical and Topographical Corps. Pedro Garcia Conde became its head and proceeded to make an accurate and detailed geographical survey of the state. Three years later the results of this survey were submitted to the governor in the form of an essay and map. The essay was printed in 1842 and described the boundaries of Chihuahua as follows:
Its boundaries are: on the north, the Territory of New Mexico; on the south, the State of Durango; on the east, the States of Coahuila and Texas; on the northwest, the State of Sinaloa. Its territorial extent is approximately three-hundredths of the Republic, or 17,151-1/2 leagues square of land which comprise all those between 25o 53’ 36" to 32o 57' 43" of north latitude and 1o 30' 16"
The map showed that the eastern boundary of Chihuahua crossed the Rio Grande at the point where the 29° parallel north latitude and the Rio Grande intersect and ran thence north until it intersected the Pecos River; thence up the Pecos River to a point located at 32° 35' north latitude for the northeast corner. Its northern boundary ran west from the northeast corner to the Mimbres River, crossing the Rio Grande near the old San Diego paraje and the Robledo Mountain; thence up the Mimbres River to its source; thence in a westerly direction to the headwaters of the Gila River, which are located at 32° 51' 43" north latitude for the northwest corner of the State. The west boundary ran in a southwesterly direction from the northwest corner down the Gila River; thence to Burro Peak; and thence in a more or less southerly direction along the continental divide into Old Mexico. On December 7, 1848 Chihuahua amended its constitution to read as follows:
The territory of Chihuahua is that which is and is now acknowledged between 25 o 53' 36" and 32 o 57' 43" of north latitude and between 1o 17" 52" of longitude west of Mexico . . .
J. A. Escudero, in his book Noticias Estadisticas, describes the Territory of New Mexico as being in the most remote part of the Republic and extending from 33o to 40o north latitude. He estimated that the territory was 185 leagues from north to south and was approximately the same distance from east to west. He stated that the territory was bounded on the north by unexplored lands, on the east by the State of Coahuila and Texas and also the Arkansas Territory of the United States; on the south, by the State of Chihuahua, and on the west, by the State of Sonora. He described the State of Sonora as covering the territory between 28 o and 32o of north latitude and 111 o and 117 o of longitude. Chihuahua, likewise, was described as covering the area between 26 o to 33 o of north latitude and 105 o to112 o latitude. 
The Territory of New Mexico, or of Santa Fe, is situated in the north, bounding on the unsettled territory of the United States. It comprehends only the valley of the Rio del Norte from 32 o N. Lat. to its source. It contains only two fertile tracts along the banks of the river and these are separated by a desert which spreads out 170 or 180 miles between 32o 30' and 35° N. Lat., and the climate is very cold: it produces only corn and the fruits of southern Europe; it affords, however, abundance of pasture for cattle and horses. This portion is the district of Santa Fe. The southern tract of fertile land is of very moderate extent, lying between 32o and 32o 30’ N. Lat.: it is called the district of the Paso del Norte. It abounds in excellent fruit, especially grapes, which, as well as the wine made of them, are in high repute all over Mexico. Wheat and Indian corn are grown extensively. The inhabitants are white, but on the mountains and deserts, which extend on both sides of the valley, there are several independent Indian tribes, which are at enmity with the settlers . . .
The State of Occidente, or of Cinaloa and Sonora united, comprehends the low plain which extends, along the Pacific, from 23o north latitude northward to the banks of the Rio del Fuerte, and, in addition, the whole of the hilly region which lies north of it . . .
The Territory of Upper California is considered to comprehend all the countries which lie to the north of the Rio Gila between the coast of the Pacific and the range of the Chippewayan Mountains. But nearly the whole of these immense countries are still overrun by savage Indian tribes, who are independent of the Mexican government. All the settlements established by the Europeans are along the tract which divides the Tule lakes from the sea, and only in those valleys which open towards the ocean. The most southern is at S. Diego, and the most northern, in the bay of S. Francisco. .
The map in front of Folson's book is especially interesting, for it depicts the Mexican states and territories as they existed on the eve of the Mexican acquisition.
A few days before James K. Polk became president, Mexico broke off diplomatic relations with the United States as a result of the annexation of Texas. Polk announced to his cabinet that he would attempt to satisfy the nation's Manifest Destiny and solve the United States-Mexico boundary problem by paying Mexico forty million dollars if it would sell New Mexico and California and agree to a permanent boundary running up the Rio Grande from its mouth to 32o north latitude and thence west to the Pacific.  Once the Mexican War started, Polk resolved that the principal facet of the peace treaty ending hostilities should be the cession of California and New Mexico to the United States. The war was less than two months old when General Stephen Watts Kearny was sent overland from Fort Leavenworth with the Army of the West. He was able to subjugate New Mexico with little difficulty. Following its surrender, Kearny, notwithstanding Texas' claim to the area east of the river, issued a Proclamation on August 22, 1846, in which he created the Territory of New Mexico with jurisdiction over all lands "within its original boundaries (on both sides of the del Norte), as a part of the United States." He also guaranteed the New Mexicans their freedom of religion and assured them that their property rights would be protected. This was enough to dispel the fears of the local inhabitants and insured the transfer of sovereignty to the United States.
Leaving the greater part of his command for use in the conquest of Chihuahua, Kearny hurried through Northern Sonora and on to California where he and Commodore Robert E. Stockton captured Los Angeles on January 10, 1847. Three days later the Mexican officials signed a treaty of capitulation, which provided that "all the property and persons of all the foreigners of each nation shall be respected, and no account shall be made of their past conduct." The war in the south also went badly for Mexico, and it surrendered following the fall of Mexico City. The war was formally terminated with the signing of the Treaty of Guadalupe Hidalgo in which Mexico ceded 338.7 million acres, or approximately forty per cent of its territory, to the United States for fifteen million dollars, plus the assumption of claims due the citizens of the United States amounting to an additional three and a quarter million dollars.
This cession covered all of New Mexico and California and the northern portion of Chihuahua and Sonora. The treaty fixed the boundary between the United States and Mexico as a line commencing:
. . . in the Gulf of Mexico three leagues from land, opposite the mouth of the Rio Grande ... thence up the middle of the river ... to the point where it strikes the southern boundary of New Mexico; thence westwardly, along the whole southern boundary of New Mexico (which runs north of the town called Paso) to its western termination; thence, northward, along the west line of New Mexico, until it intersects the first branch of the river Gila; ... thence down the middle of said branch and of said river, until it empties into the Rio Colorado; thence across the Rio Colorado, following the division line between Upper and Lower California to the Pacific Ocean.
The southern and western boundaries of New Mexico were to be determined in accordance with those depicted on the Disturnell map, which was attached to the treaty as an exhibit.
After the Treaty of Guadalupe Hidalgo had been signed, a number of questions arose which disturbed the “concord, harmony and mutual confidence” of the "good neighbors.” The principal problem was a dispute over the location of the international boundary of New Mexico. The Joint Boundary Commission, which had been appointed by the United States and Mexico pursuant to Article V of the treaty, met in California and adjourned after having established the boundary west of the Gila and Colorado rivers. It was agreed that the Joint Commission would reconvene at El Paso del Norte on the first Monday in November, 1850. Following the adjournment, the American Commissioner was removed, and John R. Bartlett was appointed as his successor. All of the American section of the Joint Commission, except its Surveyor, Andrew B. Gray, who had traipsed off to Washington, D.C., arrived at El Paso del Norte on November 13, 1850. Two days later, the Joint Commission formally reconvened. In this and subsequent meetings, perplexing questions were raised as a result of the gross errors found in the Disturnell Map. The most serious problem was the termination of the exact location on the ground of the southern boundary of New Mexico as depicted on the map. Two errors in the map made such a determination difficult, if not impossible. The first error concerned the location of El Paso del Norte, which was shown on the map as being located at 32° 15' north latitude, while its true position was 31° 45'. Thus, the town was depicted on the map approximately thirty-four miles too far north, or only eight miles south of the New Mexico boundary, as drawn on the map. The map also showed the southern boundary of New Mexico as intersecting the Rio Grande at 32° 22' north latitude. Therefore, the issue was whether the Initial Point of the International Boundary on the Rio Grande should be located at 32° 22' north latitude or eight miles north of EI Paso del Norte. The second error pertained to the location of the Rio Grande, which was placed on the map, about two degrees of longitude east of its true position. If the length of the southern boundary of New Mexico west of the river was held to its location according to longitude, it would turn northward at the 107o 40' parallel west of Greenwich, or approximately one degree west of the true location of the river. However, the boundary was shown on the map as extending westward from the river a distance of three degrees before turning due north to strike the Gila. Pedro Garcia Conde, the Mexican Commissioner, contended that the International Boundary should be located according to the grid system of longitude and run west one degree. Bartlett, on the other hand, argued that the boundary should be located in relation to the two natural objects depicted on the map -the Town of El Paso del Norte and the Rio Grande. Thus, the boundary would commence at a point about eight miles north of El Paso del Norte and run west three degrees. Garcia flatly rejected Bartlett's interpretation on the ground that it would deprive the States of Chihuahua and Sonora of a strip of land about 116 miles long and 34 miles wide. He insisted that the Treaty evidenced no intention of covering any land owned by those states. 
The obvious solution to the dilemma was a compromise. Both sides had reasons which would make such an approach attractive. Garcia was well aware that a dismemberment of the States of Chihuahua and Sonora would be vigorously protested in Mexico. Thus, he was extremely anxious to have the International Boundary located as near as possible to the true Chihuahua-New Mexico boundary. The discovery of gold in California made Bartlett extremely conscious of the value of national resources. Therefore, he was willing to yield on his position concerning the north-south location of the boundary, in order to guarantee its extension, a distance of three leagues west of the Rio Grande, and thereby place the rich Santa Rita copper mine within the United States. It would have been lost if the boundary was limited to a distance of one league west of the river. On Christmas Day, 1850, a compromise was finally reached, which established the southern boundary of New Mexico as a line commencing on the Rio Grande at 32° 22' north latitude, or 42 miles north of El Paso del Norte, and running thence west three degrees, or 175 miles. While either the Initial Point on the Rio Grande or the southwestern corner of New Mexico, as fixed by the Compromise, may be separately justified as being correctly located pursuant to the Treaty map, the two points taken together cannot be reconciled, since their locations were based upon inconsistent theories of interpretation such are the things of which all true compromises are made.
Gray's continued absence caused Bartlett no little embarrassment, and even threatened the compromise, since Article V of the treaty required all of the members of the Joint Commission to agree upon decisions. When the Joint Commission met on April 24, 1851 to accept and approve the monument which had been erected to mark the Initial Point, Garcia called this provision to Bartlett's attention. Not knowing when Gray might arrive and being unwilling to further delay the survey, Bartlett appointed Lieutenant Amiel W. Whipple as Surveyor ad interium for the United States. The agreement accepting the Initial Point was then signed. 
On July 19, 1851, the long truant American Surveyor finally arrived at Santa Rita del Cobre, the site at which the Joint Commission was then camped. At a meeting of the Joint Commission held on the following day, he was asked to ratify the proceedings which had been conducted in his absence. After studying the Minutes, he boldly announced that he could not approve the compromise since it established the Initial Point too far north, and thereby retroceded to Mexico a large and important portion of the territory transferred to the United States under the treaty. He argued that since the treaty made no reference to longitude and latitude, the boundary should have been located in the same relation to El Paso del Norte that it had on the map.
The Bartlett-Gray dispute over the proper location of the Initial Point on the Rio Grande developed into major political question in the United States. The matter was finally brought to a head when Congress ordered that none of the money which had been appropriated for the survey of the boundary could be used until it was satisfactorily proven to the President that the southern boundary of New Mexico had not been established further north of El Paso del Norte than as shown on the Disturnell Map. After examining the facts surrounding the dispute, President Millard Fillmore concluded that the money could not be used. Therefore, Secretary of Interior Alexander Stuart ordered Bartlett to discontinue further operations. Bartlett disbanded the American section of the Joint Commission on December 22, 1852, and sold most of his equipment and animals in order to pay off his men.
In addition to the embarrassment created by its failure to honor the Bartlett-Garcia Compromise, the United States realized that it would be virtually impossible to contain the hostile Indians residing in the Southwest from raiding into Mexico, and its exposure to damage claims under Article XI of the Treaty of Guadalupe Hidalgo as a result of such pillage could be considerable. Therefore, the United States decided it would be in its best interest to enter into a new treaty with Mexico. James Gadsden was appointed Minister to Mexico by President Franklin Pierce with instructions to negotiate a treaty which would settle every cause of disagreement which might interfere in any manner with the better friendship and intercourse between the two nations. Mexico was willing to negotiate because it was out of funds and had no European allies. Upon his arrival in Mexico City, Gadsden notified Santa Ana that the disputed area was absolutely essential for the construction of a transcontinental railroad to California. Gadsden made it clear to the Mexican President that if Mexico would peacefully cede the desired territory to the United States, it would receive a fair indemnity, otherwise its "imperious necessity" would compel the United States to "occupy it in one way or the other." Confronted with this dire threat, Santa Ana had no alternative but to capitulate. However, the "indemnity" demanded by Mexico was not cheap. In exchange for a 29,142,400 strip lying south of the Gila River the abrogation of its responsibility for its Indians, and certain other rights, the United States paid Mexico the sum of ten million dollars. The purchase, which is generally known as the Gadsden Purchase, was formalized in a treaty dated December 30, 1853. This treaty fixed the boundary between the United States and Mexico as follows:
Beginning in the Gulf of Mexico, three leagues from land opposite the mouth of the Rio Grande . . . ; thence ... up the middle of that river to the point where the parallel of 31° 47' north latitude crosses the same; thence south to the parallel of 31° 20' north longitude; thence along the said parallel of 31° 20' to the 111th meridian of longitude west of Greenwich; thence in a straight line to a point in the Colorado River twenty English miles below the junction of the Gila and Colorado Rivers; thence up the middle of said Colorado until it intersects the present line between the United States and Mexico.
Under t he Treaty of Guadalupe Hidalgo, the vast area north of the boundary prescribed in Article V became a part of the United States. Washington took the position that the termination of the war left the exiting local governments in operation until Congress could establish 67territorial governments. The Compromise of 1850, among other things, provided for the purchase of the area east of 68 the Rio Grande from Texas, the admission of California into the Union as a state, and the creation of the Territories of New Mexico and Utah.
Commencing at the point of the intersection of forty-second degrees of north latitude with the one hundred and twenty degrees of longitude west from Greenwich, and running south on the line of said one hundred and twenty degrees of west longitude until it intersects the thirty-ninth degree of north latitude; thence running in a straight line in a southeasterly direction to the river Colorado, at a point where it intersects the thirty-fifth degrees of north latitude; thence down the middle of the channel of said river to the boundary line between the United States and Mexico as established by the treaty of May 30, 1848; thence running west along said boundary line to the Pacific Ocean, and extending therein three English miles; thence running in a northwesterly direction and following the direction of the Pacific Coast to the forty-second degree of north latitude; thence on the line of said forty-second degrees 9f north latitude to the place of beginning. Also all the islands, harbors, and bays, along and adjacent to the Pacific Coast.
The Territory of Utah, as originally organized, covered most of the northern portion of the territory embraced within the Mexican Cession of 1848. Its boundaries were described as:
All that part of the territory of the United States within the following limits, to-wit: Bounded on the west by the State of California; on the north by the territory of Oregon; and on the east by the summit of the Rocky Mountains, and on the south by the thirty-seventh parallel of north latitude...
The southern boundary of Oregon was the forty-second parallel of north latitude, which formed the boundary between the United States and Mexico under the Treaty of 1828.  The Territory of Utah was reduced in 1861 with the formation of the Territories of Nevada and Colorado. Additional portions of the Utah Territory were added to Nevada in 1864and 1866, Idaho in 1863, and Wyoming in 1868. The present boundaries of Utah are:
Commencing with the intersection of the forty-second parallel of latitude with the thirty-fourth meridian of longitude west from Washington; running thence south on this meridian to the forty-first parallel of latitude; thence east on this parallel to the thirty-second meridian of longitude; thence south on this meridian to the intersection with the thirty-seventh parallel of latitude; thence west upon this parallel of latitude to its intersection with the thirty-seventh meridian of longitude; thence north on this meridian to its intersection with the forty-second parallel of latitude; thence east on the forty-second parallel of latitude to the place of beginning.
The Territory of Nevada, as organized by Act of March 2, 1861consisted of the following described lands which were taken from Utah:
Beginning at the point of intersection of the forty-second degree of north latitude with the thirty-ninth degree of longitude west from Washington; thence running south on the said thirty-ninth degree of west longitude, until it intersects the northern boundary line of the Territory of New Mexico; thence due west to the dividing ridge separating the waters of Carson Valley from those that flow into the Pacific; thence on said dividing ridge northwardly to the forty-first degree of north latitude; thence due north to the southern boundary of the State of Oregon; thence due east to the place of beginning.
Since the above described limits covered a small portion of the State of California, which it refused to relinquish, Congress, by Act of July 14, 1862, revised Nevada's dimensions by taking a fifty-mile strip of land west of the thirty-eighth meridian west of Washington from Utah and adding it to Nevada. Nevada was further enlarged on May 5, 1866, with the addition of the following described tracts which were taken from Utah and Arizona:
All that territory and tract of land adjoining the present State of Nevada, and lying between the thirty-seventh and forty-second degrees of north longitude and west of the thirty-seventh degree of longitude west of Washington.
Commencing on the thirty-seventh degree of north latitude at the thirty-seventh degree of longitude west of Washington, and running thence south on said degrees of longitude to the middle of the river Colorado of the West, thence down the middle of said river to the eastern boundary of the State of California; thence northwesterly along said boundary of California to the thirty-seventh degree of north latitude; and thence east along said degree of latitude to the point of beginning.
The present State of Nevada is bounded as follows:
On the east, by the thirty-seventh meridian west of Washington; on the south, by the middle of the Colorado River to the thirty-fifth parallel; on the southwest by the California line; on the west, by the one hundred-twentieth meridian of longitude; and on the north, by the forty-second parallel.
The boundaries of the Territory of New Mexico were described in the Act of September 9, 1850, as follows:
Beginning at a point in the Colorado River, where the boundary line with the Republic of Mexico crosses the same; thence eastwardly with the said boundary line to the Rio Grande; thence following the main channel of said river to the parallel of the thirty-second degree of north latitude; thence east with said degree to its intersection with the one hundred and third degree of 101gitude west of Greenwich; thence north with said degree of longitude to the parallel of thirty-eight degrees of north latitude; thence west with said parallel to the summit of the Sierra Madre; thence south with the crest of said mountain to the thirty-seventh parallel of north latitude; thence west with said parallel to its intersection with the boundary line of the State of California, thence with said boundary line to the place of beginning.
The Territory of New Mexico was enlarged with the addition of all of the Gadsden Purchase on August 4, 1854, but was reduced as a result of the formation of the Territory of Colorado in 1861 and the Arizona Territory in 1863. New Mexico's present boundariesare as follows:
Beginning at the point of intersection of the 103rd meridian of longitude west of Greenwich with the 37th parallel of latitude; running thence south to its point of intersection with the 32nd parallel of latitude; thence west on this parallel to its intersection with the Rio Grande; thence southerly down the main channel of the Rio Grande as it was September 9, 1850, to its point of intersection with the boundary line between the United States and Mexico; thence with this boundary to its intersection with the 32nd meridian of longitude west from Washington; thence north along this meridian to the 37th parallel of latitude, and east along that parallel to the place of beginning.
Colorado was organized as a Territory by Congress on February 28, 1861, and included within its boundaries are parts of the lands obtained from the Louisiana Purchase, the Texas Acquisition, and the First Mexican Cession of 1848. The famous San Luis Valley was taken from New Mexico and included in the new Territory. Colorado's boundarieswere described as follows:
Commencing at a point formed by the intersection of the thirty-seventh degree of north latitude with the twenty-fifth degree of longitude west from Washington; extending thence due west along said thirty-seventh degree of north latitude to a point formed by its intersection with the thirty-second degree of longitude west from Washington; thence due north along said thirty-second degree of west longitude to a point formed by its intersection with the forty-first degree of north latitude; thence due east along said forty-first degree of north latitude to a point formed by the intersection with the twenty-fifth degree of longitude west from Washington; thence due south along said twenty-fifth degree of west longitude.
The western portion of the Territory of New Mexico was carved out on February 24, 1863, and organized into the Territory of Arizona. It was described as being:
All that part of the present Territory of New Mexico situated west of a line running due south from the point where the southwest corner of the Territory of Colorado joins the northern boundary of the Territory of New Mexico to the southern boundary line of said Territory of New Mexico...
In 1866 the portion of Arizona lying north of the middle of the Colorado River and west of the thirty-seventh meridian west of Washington was given to Nevada. Thus, the present boundaries of Arizona  are as follows:
Beginning at the point of intersection of the thirty-seventh parallel of latitude with the thirty-second meridian of longitude west from Washington; thence south along this meridian to its intersection with the boundary line between the United States and Mexico; thence with this boundary to the Colorado River; thence up the middle of the main channel of the Colorado River to its point of intersection with the thirty-seventh parallel; and eastward along the thirty-seventh parallel to the place of beginning.
Within the areas ceded to the United States by Mexico in 1848 and 1853 and by Texas in 1850, there are a vast number of Spanish and Mexican Land Grants. The area generally known as the Southwest was comprised of only the present states of New Mexico, Arizona, Utah and Colorado, or the "Four Corner States." The Southwestern Spanish and Mexican Land Grants are located in New Mexico and the southeast portions of Arizona and Colorado .
Burns, "The Spanish Land Laws of Louisiana," 11 Louisiana Historical Quarterly 560-561 (1928) .
2 Miller, Treaties and Other International Acts of the United States of America, 508-509 (1931).
Ibid., 498-505. Prior to the Treaty of 1763, the east boundary of Louisiana had been the Perdido River. In a letter dated December 21, 1804, Talleyrand advised Charles Pinkney, the American Minister, that Spain had not retroceded any part of the territory then known as West Florida to France in 1800. Louisiana had been receded to France "with the same extent it now has in the hands of Spain, and that it had when France possessed it, and such as it should be ... " France ceded Louisiana to the United States by the same description. The opportunity thus presented for conflicting claims was obvious and John Marshal remarked that the treaty was formed in terms of "studied ambiguity."
3 Miller, Treaties and Other International Acts of the United States of America, 3-18 (1933).
 Wislizenus, in describing the boundaries of New Mexico in 1848, states, “If we accept now in all directions the widest boundaries for New Mexico, it would extend from 32o 3’ to 42o north latitude, and from 100o to about 114o longitude west from Greenwich. But as the country of the wild Indians has never been under any jurisdiction or control of the Mexicans, and settlements have never extended over the territory, the name of New Mexico has generally been applied only to the settled country between the 32o and 38o latitude north, and from about 104o to 108o longitude west of Greenwich. In this limited extent, whose lines are drawn by custom, gradual development, and natural connection, it will be most convenient at present to consider New Mexico.” Wislizenus, Memoir of a Tour to Northern Mexico, 22 (1848).
 Richman, California Under Mexico and Spain, 493-494 (1965).
 5 Miller, Treaties and Other International Acts of the United States of America, 207-236 (1937).
 These payments were made to satisfy the policy, which had been judicially and politically declared, that a war would not be prosecuted by the United States for acquisition of territory. Fleming v. Page, 9 How. (50 U.S.) 603 (1850) .
 Caveat: The Court of Private Land Claims dismissed the plaintiff's petition in City of Ysleta v. United States on the ground that it did not have jurisdiction in the case, which covered land east of the Rio Grande. The court held that the United States acquired the area from Texas and not under the Treaty of Guadalupe Hidalgo. City of Ysleta v. United States, No. 33 (Mss., Records of the Ct. Pvt. L. Cl.).
 5 Miller, Treaties and Other International Acts of the United States of America, 207-236 (1937).
An Act making appropriations for the Civil and Diplomatic Expenses of the Government for the year ending the thirtieth of June, Eighteen Hundred and Fifty Three, and for other purposes. Chap. 108, 10 Stat. 76 (1855).
 Bartlett, Personal Narratives of Exploration and Incidents in Texas, New Mexico, California, Sonora and Chihuahua, 514-517 (1854).
 Griggs, History of the Mesilla Valley or the Gadsden Purchase, 44 (1930).
 In this connection, it should be noted that the United States acquired much more territory than covered by the Bartlett-Gray dispute. The disputed area covered only 3.8 million acres, or about thirteen per cent of the land acquired by the United States under the Gadsden Purchase.
 6 Miller, Treaties and Other International Acts of the United States of America, 293-437 (1942).
 5 Miller, Treaties and Other Terr1torlal Acts of the United States of America, 207-236 (1937).
 2 Twitchell, Leading Facts of New Mexican History, 265-266 (1912).
Compromise of 1850 (Texas and New Mexico) Chap. 49, 9 Stat. 446 (1850).
Compromise of 1850 (California) Chap. 50, 9 Stat. 452 (1850).
Compromise of 1850 (Texas and New Mexico) Chap. 49, 9 Stat. 446 (1850).
Compromise of 1850 (Utah) Chap. 51, 9 Stat., 453 (1850.
 Douglas, Boundaries, Areas, Geographic Centers and Altitudes of the United States and the Several States. 242-243 (1932).
An Act to Establish a Territorial Government of Utah, Chap. 51, 9 Stat., 453 (1850).
 3 Miller, Treaties and Other International Acts of the United States of America, 405-411 (1933).
 Douglas, Boundaries, Areas, Geographic Centers and Altitudes of the United States and the Several States, 231 (1932).
An Act to Organize the Territory of Nevada, Chap. 83, 12 Stat., 209 (1861).
An Act to Extend the Territorial Limits of the Territory of Nevada, Chap. 173, 12 Stat., 575 (1862); and An Act to Enable the People of Nevada to Form a Constitution and State Government, and For The Admission of Such State Into The Union on an Equal Footing With The Original States, Chap. 34, 13 Stat., 30 (1864).
An Act Concerning the Boundaries of the State of Nevada, Chap. 73, 14 Stat. 43 (1866).
An Act to Provide a Temporary Government for the Territory of Colorado, Chap. 59,12 Stat., 172 (1861).
An Act to Enable the People of Colorado to Form a Constitution and State Government, and for the Admission of the said State Into the Union on an Equal Footing With the Original States. Chap. 139, 18 Stat., 474 (1875).
An Act to Provide a Temporary Government for the Territory of Arizona and for Other Purposes. Chap. 54, 12 Stat., 664 (1863).
 Douglas, Boundaries, Areas, Geographic Centers and Altitudes of the United States and the Several States, 233 (1913).