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: Read more below: Spot Resolutions and Civil Disobedience: American opposition to the war
Henry David Thoreau
Learn more about Transcendentalist author Henry David Thoreau, an opponent of the Mexican-American War. What did the U.S. gain by winning the Mexican-American War? Under the Treaty of Guadalupe Hidalgo, which settled the Mexican-American War, the United States gained more than 500,000 square miles (1,300,000 square km) of land, expanding U.S. territory by about one-third. Mexico ceded nearly all the territory now included in the U.S. states of New Mexico, Utah, Nevada, Arizona, California, Texas, and western Colorado for $15 million and U.S. assumption of its citizens’ claims against Mexico. Treaty of Guadalupe Hidalgo
Read more about the Treaty of Guadalupe Hidalgo. How the Border Between the United States and Mexico Was Established
Learn more about how the borders of the United States and Mexico were changed by the Mexican-American War. How did the Mexican-American War increase sectionalism in the United States? The Mexican-American War reopened the slavery-extension issue, which divided the North and South and which had been largely dormant since the Missouri Compromise.