Treaty of Guadalupe Hidalgo

February 1848- defeated Mexicans made peace with the Americans.

  • Treaty of Guadalupe Hidalgo- forced Mexico to give up the northern 1/3 of their country which added 1.2 million square miles to the US
    • US kept New Mexico and California
    • US would return Mexico City to the Mexicans
    • US would “purchase” New Mexico and California for $15 million
    • secured the Rio Grande as the southern boundary of Texas

The treaty angered Mexican who remained bitter towards the US

Polk was also angry by the treaty and blamed his negotiator, Nicholas Trist, for settling for too little after such a thorough victory



  • Gadsden Purchase- (1853) The US purchased another 29,640 square miles in southern Arizona and New Mexico in order to build a railroad across the continent.  The railroad was thought to need a southerly route because of the Rocky Mountain challenge