In March 1845, shortly before leaving office, President John Tyler signed a Joint Resolution of Congress offering to annex the Texas Republic to the United States. Mexico, which had never recognized the Republic and still claimed Texas as its…

On April 26, 1846, following a tense stand-off between U.S. and Mexican troops on the banks of the Rio Grande (which the U.S. now claimed as its border with Mexico, having annexed the state of Texas), a small patrol of sixty-three U.S. soldiers was…

Before being replaced by General Arista, General Francisco Mejía was the commander of the Mexican army at Matamoros, facing the American forces at Fort Texas on the opposite side of the Rio Grande. In this elaborately-worded proclamation, General…

In this editorial, published on May 2nd, 1846, Brooklyn Eagle editor and poet Walt Whitman notes the growing "war-fever" that had gripped the nation in recent months. In fact, the "lighted match" which sparked the U.S. to wage war against Mexico had…

This 1847 recruiting poster urges the men of Holmes County, Ohio to enlist for duty in the war against Mexico. The war was fought by the standing, or regular, U.S. army, alongside volunteers. The U.S. War Department first issued a call for states to…

Theodore Parker, a well-known abolitionist and Congregationalist minister, delivered the following sermon to an antiwar group gathered in Boston in June 1846.

John C. Calhoun, Senator from South Carolina and future spokesman for southern secession, delivered the following speech to Congress on January 4, 1848. At the time, U.S. and Mexican diplomats were in the midst of negotiating a peace treaty to…

In this lesson students read a series of documents about the American and Mexican reasons for and against the 1846 U.S.-Mexico War. As they read the documents students identify when the authors employ various foreign policy ideologies such as…

The Treaty of Guadalupe Hidalgo, which ended the Mexican-American War in 1848, ceded 525,000 square miles--55% of--Mexican territory to the United States. In exchange, the United States paid approximately $15 million in damages to pay for…