The Treaty of Guadalupe Hidalgo in 1848 resulted in the United States acquiring territories such as California, Nevada, Utah, and Arizona from Mexico after the Mexican-American War. Texas was already annexed before this treaty. The acquisition played a critical role in American westward expansion.
;
The Treaty of Guadalupe Hidalgo in 1848 resulted in the United States acquiring territories including California, Nevada, Utah, and Arizona from Mexico. This treaty ended the Mexican-American War and significantly expanded U.S. territory. Texas had already been annexed prior to this treaty in 1845. ;