The treaty that ended the Mexican-American War in 1848 was the Treaty of Guadalupe Hidalgo. Signed on February 2, 1848, it required Mexico to cede a large portion of its northern territory to the United States, which included present-day California, Arizona, New Mexico, Nevada, Utah, and parts of Colorado and Wyoming. In exchange, the U.S. paid Mexico $15 million and assumed certain claims by U.S. citizens against the Mexican government. This treaty significantly expanded U.S. territory, fulfilling the idea of Manifest Destiny while also fueling tensions over slavery in the newly acquired lands.