Mexican Cession of 1848 was a large area of land that Mexico turned over to the United States following the Mexican War (1846-1848). Under the Treaty of Guadalupe Hidalgo, Mexico ceded, (surrendered) land that now makes up California, Nevada, Utah, most of Arizona, and parts of Colorado, New Mexico, and Wyoming.
Americans in Texas revolted against the Mexican government in 1835. They formed the Republic of Texas the following year. After Texas became a U.S. state in 1845, Mexico broke off relations with the United States. The countries disagreed over a number of issues, including Texas’s southern boundaries. At the time, many people in the United States supported the idea of manifest destiny. Manifest destiny was a belief in the inevitable territorial expansion of the United States.
The Mexican War began in June 1846. American forces quickly expelled Mexican troops from parts of California, New Mexico, and Texas. The U.S. Army occupied Mexico City, the Mexican capital, in September 1847.
In February 1848, Mexico signed an agreement that officially ended the war. Under the terms of the Treaty of Guadalupe Hidalgo, the U.S. government paid Mexico $15 million for about 525,000 square miles (1,360,000 square kilometers) of territory. The U.S. government also took responsibility for $3 million in payments that the government claimed Mexico owed to American citizens.
See also Guadalupe Hidalgo, Treaty of ; Mexican War .