When was the last time United states and Mexico fought war?

The United States and Mexico last fought a war in the 19th century. The Mexican-American War, which lasted from 1846 to 1848, was a conflict between the United States and Mexico over the annexation of Texas by the United States and territorial disputes in the Southwest. The United States won the war and Mexico ceded a vast amount of territory to the United States, including present-day California, Nevada, Utah, Arizona, New Mexico, and parts of Colorado and Wyoming.