Title: Mexican-American War | Significance, Battles, Results, Timeline, & Facts | Britannica
Headings: Mexican-American War
Mexican-American War
Mexico-United States [1846–1848]
See how President Polk's administration won the Mexican-American War but failed to solve the slavery debate
What was the Mexican-American War?
What did the Mexican-American War have to do with Manifest Destiny?
Was there opposition to the Mexican-American War within the United States?
What did the U.S. gain by winning the Mexican-American War?
How did the Mexican-American War increase sectionalism in the United States?
“American blood on American soil”: Polk and the prelude to war
Spot Resolutions and Civil Disobedience: American opposition to the war

Content: The Mexican-American War was a conflict between the United States and Mexico, fought from April 1846 to February 1848. Won by the Americans and damned by its contemporary critics as expansionist, it resulted in the U.S. gaining more than 500,000 square miles (1,300,000 square km) of Mexican territory extending westward from the Rio Grande to the Pacific Ocean. It stemmed from the annexation of the Republic of Texas by the U.S. in 1845 and from a dispute over whether Texas ended at the Nueces River (the Mexican claim) or the Rio Grande (the U.S. claim). What did the Mexican-American War have to do with Manifest Destiny? The concept of Manifest Destiny held that the United States had the providential right to expand to the Pacific Ocean. In 1845 the U.S. annexed the Republic of Texas, which had won de facto independence from Mexico in the Texas Revolution (1835–36). When U.S. diplomatic efforts to establish agreement on the Texas-Mexico border and to purchase Mexico’s California and New Mexico territories failed, expansionist U.S. Pres. James K. Polk found a rationale to justify an attempt to take that land by force when U.S. and Mexican troops skirmished north of the Rio Grande on April 25, 1846. Manifest Destiny
Read more about Manifest Destiny. James K. Polk
Read about James K. Polk, during whose presidency the United States acquired vast territories along the Pacific coast and in the Southwest.