The Mexican Cession refers to the territory ceded to the United States by Mexico through the Treaty of Guadalupe Hidalgo in 1848. As a result of the Mexican-American War, Mexico was forced to give up roughly 55% of its territory, including present-day California, Nevada, Utah, Arizona, and parts of Colorado, Wyoming, New Mexico, and Texas. This significant territorial acquisition by the United States further expanded its borders and set the stage for ongoing conflicts and negotiations over the issue of slavery in the newly acquired territories. The Mexican Cession played a crucial role in shaping the political, economic, and social landscape of the southwestern United States.
