Who did the united stated defeat in 1848?

In 1848, the United States defeated Mexico in the Mexican-American War, which lasted from 1846 to 1848. The conflict was primarily over territorial disputes following the annexation of Texas. The war concluded with the signing of the Treaty of Guadalupe Hidalgo, resulting in the U.S. acquiring significant territories, including present-day California, Arizona, New Mexico, and parts of Colorado, Utah, and Nevada.