The treaty that concluded the conflicts between the U.S. and Mexico in 1848 is known as the Treaty of Guadalupe Hidalgo. This treaty formally ended the Mexican-American War and resulted in significant territorial gains for the United States, including 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 debts. The treaty not only expanded U.S. territory but also intensified debates over slavery in the new territories, significantly influencing the political landscape leading up to the Civil War.