History glossary
Mexican-American War
the 1846-1848 war in which the United States defeated Mexico and gained vast western territories.
- Category
- War
- Region
- North America
- Date range
- 1846-1848
What it means
The Mexican-American War was fought from 1846 to 1848 between the United States and Mexico. The Treaty of Guadalupe Hidalgo transferred California, New Mexico, and other western lands to the United States, reopening the conflict over whether slavery would expand westward.
