Which conflict led to the U.S. acquisition of the Mexican Cession?

The Mexican-American War was a pivotal conflict that occurred between 1846 and 1848, primarily over territorial disputes following the annexation of Texas by the United States. This war was instrumental in expanding U.S. territory, as it resulted in the Treaty of Guadalupe Hidalgo, which ultimately ceded a vast area of land to the United States, known as the Mexican Cession. This territory included present-day California, Nevada, Utah, Arizona, and parts of Colorado and New Mexico, significantly shaping the future of the American West and fulfilling the concept of Manifest Destiny.

While the Spanish-American War, the Civil War, and the War of 1812 were important conflicts in U.S. history, they did not directly result in the acquisition of territories from Mexico like the Mexican-American War did. Therefore, the Mexican-American War is the correct answer as it directly led to this significant expansion of U.S. territory through military engagement and subsequent treaty negotiations.