(Feb. 2, 1848) Treaty between the U.S. and Mexico that ended the Mexican War , named for the Mexico City neighbourhood where it was signed.
It drew the U.S.-Mexico boundary at the Rio Grande and the Gila River. For $15 million the U.S. received more than 525,000 sq mi (1.36 million sq km) of land and agreed to settle the more than $3 million in claims made by U.S. citizens against Mexico. By leaving Mexicans unsure of their country's future and reopening the question of the expansion of slavery in the vast territory ceded to the U.S., the treaty was a factor in the civil wars that followed in both countries.