The United States-Mexican boundary controversy, 1848-1853

The purpose of this research is to shed some new light on the controversy between the United States and Mexico concerning the boundary between the respective countries. This controversy began in 1845 following the Treaty of Guadalupe Hidalgo which ended the Mexican-American War and lasted until the Gadsden Treaty of 1853. There were several issues which remained unsettled following the signing of the treaty and which almost caused another war between the two countries. The three main issues were: (1) The use of the inaccurate Disturnell map for boundary purposes; (2) The Mesilla Strip by which Mexico was given several thousand square miles of land in New Mexico and Arizona by the Bartlett-Conde Compromise (later declared invalid by President Franklin Pierce); and (3) Article XI of the Treaty of Guadalupe Hidalgo by which terms the United States promised the northern states of Mexico protection from Indian raids from United States territory. This paper proposes not only to bring the boundary controversy and the issues involved into focus, but also show why the United States did not annex lower California and why the mouth of the Colorado River was not included in the treaty which determined the final boundary. This paper will also discuss the internal arguments among the members of the UnitedStates Boundary Commission and how they affected the survey. Regional differences in the United States and the search for a southern railroad route to the Pacific also affected the final settlement of the boundary. A re-examinationof the issues of the period from 1848 to 1853 will show how the southern boundary was finally determined, and how the final boundary agreed upon was a necessary solution of problems affecting relations between the two countries.