By the time the Mexican War ended, many people in the United States wanted to annex all Mexico. But the Treaty of Guadalupe Hidalgo (signed on February 2, 1848) required Mexico to give up only the territory Polk had originally asked for -- the Rio Grande region, New Mexico, and California. The United States paid Mexico $15 million for this territory, known as the Mexican Cession, which included all or parts of what are now the states of California, Nevada, Utah, Wyoming, Colorado, New Mexico, and Arizona. In 1853, the Gadsden Purchase gave an additional 29,640 square miles to the United States.
This page was last updated on 04/19/2011.