Treaty of Guadalupe Hidalgo

The war grew out of the United States' annexation of Texas in 1845 and an unresolved dispute over its southern boundary. Mexico did not accept the annexation, and the two governments claimed different border rivers, the Nueces and the Rio Grande. An unsuccessful American diplomatic mission preceded the fighting of 1846. By the time serious peace negotiations became possible, American troops occupied Mexico City and the settlement would determine far more than the Texas boundary. [1]

Nicholas Trist signed the Treaty of Guadalupe Hidalgo on 2 February 1848, after American troops had occupied Mexico City. President James K. Polk had already recalled him, but Trist stayed and negotiated anyway, concluding that a workable peace was within reach. [2]

The settlement cost Mexico more than half its territory. It established the Rio Grande as the Texas boundary and transferred the northern lands extending to the Pacific. The United States agreed to pay $15 million and assume specified claims owed to American citizens. Mexico negotiated these terms with its capital under occupation and its army defeated. [2]

Mexican residents of the transferred territory could remain or move to Mexico, with a period in which those who stayed could choose their nationality. The treaty also addressed their property, although the U.S. Senate removed a separate article explicitly protecting Mexican land grants before approving the agreement in March. Ratifications were exchanged in May, bringing the war to an end under terms that governed people whose homes now lay in another country. [2]

Polk's October 1847 recall took about six weeks to reach Trist; meanwhile, Mexico had named Bernardo Couto, Miguel Atristain, and Luis Gonzaga Cuevas to negotiate. The treaty specified procedures for ending hostilities, withdrawing troops, and restoring customs houses to Mexican control. [2]

Citizenship, Property, and the New Boundary

Articles VIII and IX addressed Mexican residents who remained in the transferred territories. Those who did not declare an intention to retain Mexican nationality within a year of the exchange of ratifications were considered to have chosen American citizenship. The treaty protected property, liberty, and religious practice, while leaving the timing of admission to the full rights of citizenship to Congress. These provisions made nationality and civil rights part of the territorial settlement. [2]

The promises of protection did not prevent extensive losses of land. In New Mexico, even community grants confirmed under American procedures subsequently passed to others through sales, tax foreclosures, lawyers’ fees, and court orders dividing common property. A later Government Accountability Office investigation distinguished these losses after confirmation from disputes over how much land American authorities initially recognized. The change in sovereignty brought different courts and property rules into people’s daily lives. [3] [4]

The treaty also provided for commissioners and surveyors to mark the new boundary. Its terms did not make every later border question disappear. The Gadsden Purchase subsequently adjusted the boundary in 1853–1854, and disagreements over rivers and land continued to require negotiation. Within the United States, the acquisition intensified the dispute over whether slavery would expand into the new territories. [2] [1]

Related Diplomats

1. Luis de la Rosa Oteiza [5] [6]

Related Reading

• Mexico and the United States