American history

The Mexican American War

The Mexican-American War from 1846 to 1848 is often viewed as motivated by American imperialism. In 1846, President James K. Polk sent soldiers to the disputed zone between Mexico and the newly annexed Republic of Texas in what most historians describe as a provocation for war.

After war broke out, American forces quickly defeated those of Mexico, and in the Treaty of Guadalupe Hidalgo, Mexico ceded its claims on what is now almost the entire Southwest and California to the United States, in exchange for $15 million and the settlement of pending individual claims against Mexico valued at about $3 million.

Many aspects of the war and its aftermath were controversial. A faction called the Continental Democrats had advocated annexing all of Mexico, some arguing that Mexico should be punished for its behavior. Others, largely in the North, denounced the war variously as imperialism and as a pro-slavery stratagem to add more slave territory to the United States.

Today, there is some question over the nature of the Mexican-American war. Most claim that it was aggressive in nature, prompted by Manifest Destiny. Among these, some historians claim that it was simply a grab for more territory, whereas others see it as part of a concerted expansionist movement, reminiscent of imperialism.