Treaty of Guadalupe-Hidalgo

Date: From 1848-02-02 to 1848-07-04

Place: Mexico City, Mexico

The Treaty of Guadalupe-Hidalgo ended the Mexican War and ceded a large amount of territory from Mexico to the United States. Negotiated by Nicholas Trist, the treaty may have yielded even larger gains (at one point the entirety of Mexico was under consideration) but intervention by President James K. Polk and timing resulted in the final agreement. Signed on February 2, 1848, ratified by the U.S. Senate with amendments on March 10, ratified by President Polk on March 16, ratifications exchanged on May 30, and proclaimed on July 4, the treaty gave the United States about 500,000 square miles of Mexican territory including all of modern Arizona, California, Nevada, New Mexico, and Utah, along with parts of Colorado and Wyoming. The treaty also settled the dispute over Texas's southern border which caused the war, setting it at the Rio Grande River. In addition to these territorial cessions, the United States gave Mexico fifteen million dollars and assumed up to $3,250,000 of the claims owed to the United States from before the war. The question of slavery's legality in all or part of this new territory set off a major sectional debate in the United States, resulting in the Compromise of 1850 and, ultimately, the Civil War.

Wallace Ohrt, Defiant Peacemaker: Nicholas Trist in the Mexican War (College Station: Texas A&M University Press, 1997); Richard Griswold del Castillo, The Treaty of Guadalupe Hidalgo: A Legacy of Conflict (Norman: University of Oklahoma Press, 1990); Treaty of Guadalupe Hidalgo [Exchange copy]; 2/2/1848; Perfected Treaties, 1778 - 1945; General Records of the United States Government, Record Group 11; National Archives Building, Washington, DC,, accessed 12 April 2023.