There shall be firm and universal peace between the United States of America and the Mexican Republic…
Article I, Treaty of Guadalupe Hidalgo, signed February 2, 1848.
The terms of the agreement confirmed U.S. claims to Texas and established the border between the U.S. and Mexico at the Rio Grande and the Gila River. The treaty also granted the U.S. more than 525,000 square miles of former Mexican territory that includes present-day California, Nevada, Utah, most of New Mexico and Arizona, and parts of Colorado and Wyoming. In exchange, the U.S. paid Mexico $15 million for the territory and agreed to assume the claims of American citizens against the Mexican government, a sum of approximately $3 million. This treaty, along with the 1853 Gadsden Purchase, completed the continental expansion of the United States.
In honor of the 150th anniversary of the treaty signing, the Library of Congress created the online exhibition The Treaty of Guadalupe Hidalgo. It includes page images of the original treaty housed in the Library of Congress Manuscript Division as well as the area map used during the negotiations from the Geography and Map Division.
The Mexican War began with a dispute over the United States annexation of Texas. In January 1846, President James K. Polk, a strong advocate of westward expansion, ordered Zachary Taylor to occupy disputed territory between the Nueces and Rio Grande rivers. Mexican troops attacked Taylor’s forces, and Congress approved a declaration of war on Mexico on May 13, 1846. With the capture, by General Winfield Scott, of Mexico City on September 14, 1847, the fighting subsided.
William T. Sherman caught war fever after hearing of Zachary Taylor’s victory at Palo Alto and Resaca de la Palma on May 8, 1846. He soon left his post as a recruiting officer in Pittsburgh and set out for New York, where he boarded a ship bound for California in hopes of joining the fighting. Sherman, who became a famous Union general in the Civil War, describes his journey and experiences of the Mexican War in Part I of his memoir, Recollections of California: 1846-1861.
Lewis Adelbert Norton, a veteran of the Canadian rebellion of 1837-39, responded to the declaration of war by raising a volunteer regiment in Kane County, Illinois. He describes his war experiences in Chapters XI through XXIV of his story, Life and Adventures of Col. L. A. Norton.
- See the entry for the Treaty of Guadalupe Hidalgo in the Library’s Primary Documents in American History webguide series.
- The Library’s Guide to the Mexican War compiles a wide variety of material associated with the Mexican War (1846-1848), including manuscripts, maps, broadsides, pictures, sheet music, books, and government documents.
- To find newspaper articles about the events of the Mexican-American War start with Mexican-American War and the Treaty of Guadalupe Hidalgo: Topics in Chronicling America.
- Explore the William T. Sherman Papers for his recollections of time spent in California during the Mexican War.
- Search on Mexican War in “California as I Saw It”: First-Person Narratives of California’s Early Years, 1849 to 1900 to locate more recollections of the conflict.
- Also, be sure to see the Today in History features on the Battle of Palo Alto and the Battle of Buena Vista, fought near Monterrey, Mexico, in 1847.