The Mexican–American War, [a] also known in the United States as the Mexican War, and in Mexico as the United States intervention in Mexico, [b] (April 25, 1846 – February 2, 1848) was an invasion of Mexico by the United States Army.

Nov 9, 2009 · It pitted a politically divided and militarily unprepared Mexico against the expansionist-minded administration of U.S. President James K. Polk, who believed the United States had a “Manifest ...

Mexico lost 55% of its territory to the United States between 1836 and 1848. The U.S. Army won every major battle in the war, but it was unable to suppress guerrilla activity, which never ceased. This was the first U.S. counterinsurgency war in a foreign country.

Mexican-American War, war between the U.S. and Mexico from 1846 to 1848. It was caused by a territorial dispute stemming from the United States’ annexation of Texas in 1845 and from contention over whether Texas ended at the Nueces River or the Rio Grande.

Tensions between the United States and Mexico rapidly deteriorated in the 1840s as American expansionists eagerly eyed Mexican land to the west, including the lush northern Mexican province of California.

It was signed on 2 February 1848 in the town of Guadalupe Hidalgo. After the defeat of its army and the fall of the capital in September 1847, Mexico entered into peace negotiations with the U.S. envoy, Nicholas Trist.

Mar 28, 2023 · 1843 — Mexico warns the United States it will declare war if it annexes Texas. 1844 — James K. Polk, who believes in America’s Manifest Destiny, is elected President of the United States.

Mar 15, 2025 · Mexico permitted American immigrants to settle in Texas under the condition that they become Mexican citizens, convert to Catholicism, and obey Mexican laws, including the 1829 abolition of slavery. ... When James K. Polk, an ardent expansionist, won the presidency in 1844, the annexation of Texas gained new momentum. Polk campaigned on a ...

Jan 19, 2025 · The main causes of the Mexican-American War were the annexation of Texas and failed negotiations with Mexico. Annexation of Texas. Settlers in Texas wanted to join the United States after gaining independence from Mexico. The annexation of Texas took place in 1845. Texas remained a republic for nine years before being annexed

Nov 9, 2009 · The Treaty of Guadalupe Hidalgo in 1848 ended the Mexican-American War, with much of the current U.S. Southwest ceded to the United States from Mexico.