Mexican War

American  

noun

1. the war between the U.S. and Mexico, 1846–48.

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Mexican War British  

noun

1. the war fought between the US and Mexico (1846–48), through which the US acquired the present-day Southwest

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Mexican War Cultural  

1. A war fought between the United States and Mexico from 1846 to 1848. The United States won the war, encouraged by the feelings of many Americans that the country was accomplishing its manifest destiny of expansion. Mexico renounced all claims to Texas north of the Rio Grande and yielded a vast territory that embraces the present states of California, Nevada, and Utah, and parts of Arizona, Colorado, New Mexico, and Wyoming.

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Many generals of the Civil War, including Ulysses S. Grant and Robert E. Lee, gained experience in battle during the Mexican War. The Mexican War was opposed by many Americans, notably by the author Henry David Thoreau, who was put in jail for refusing to pay a tax to support the war. His essay “Civil Disobedience” explains the principles of his action.

Example Sentences

Thoreau spent a night in jail for refusing to pay a poll tax, objecting to slavery and the Mexican War.

From MarketWatch • Apr. 6, 2026

That book is a Pulitzer Prize-winning account of America during the turbulent years from the end of the War of 1812 to the end of the Mexican War in 1848.

From Salon • Jul. 26, 2025

The same fate befell a similar monument to Jose Maria Morelos, one of the leaders of the Mexican War of Independence.

From Los Angeles Times • Jan. 4, 2023

Isabel Cañas’ “The Hacienda,” a shivery haunted-house tale set in the aftermath of the Mexican War.

From Seattle Times • Oct. 21, 2022

“Grandma, the Mexican War started almost ninety years ago. Even if Uncle Grady is a hundred and three, he’d only have been about my age during that war.”

From "A Long Way from Chicago" by Richard Peck