Treaty of Guadalupe Hidalgo: This treaty ended the Mexican-American War in 1848 and established peace between Mexico and the United States. It also resolved many territorial disputes by ceding vast amounts of land from Mexico to the U.S.
Compromise of 1850: This legislation aimed to address ongoing territorial disputes arising from the Mexican-American War by allowing popular sovereignty (the people's vote) in determining whether new territories would allow slavery or not.
Gadsden Purchase: As another resolution to territorial disputes, this agreement in 1853 allowed for the purchase of additional land from Mexico, mainly for railroad construction purposes.