The Mexican-American War of 1846-1848 was a pivotal conflict that reshaped North America. Sparked by U.S. expansionism and disputes over Texas, it ended with Mexico ceding vast territories to the United States through the Treaty of Guadalupe Hidalgo. This war had far-reaching consequences, altering the political landscape and deeply impacting Mexican-Americans. It fueled debates over slavery, intensified racial tensions, and set the stage for ongoing border issues between the U.S. and Mexico that persist to this day.