Mexican-American War Overview

Timeframe and Location

• Lasted from April 1846 to February 1848.
• Fought between the United States and Mexico.
• Major locations include Texas, Mexico, and the U.S. Southwest.

Key Figures

• United States: President James K. Polk, General Zachary Taylor, General Winfield Scott.
• Mexico: President Antonio López de Santa Anna.

Causes

• Stemmed from the U.S. annexation of Texas in 1845.
• Dispute over the Texas border—Nueces River (Mexican claim) vs. Rio Grande (U.S. claim).
• Manifest Destiny ideology encouraged U.S. expansion.

Major Battles

• Battle of Palo Alto (May 8, 1846)
• Battle of Buena Vista (February 22–23, 1847)
• Battle of Cerro Gordo (April 1847)
• Battle of Chapultepec (September 12–14, 1847)

Political Context

• U.S. President Polk's aggressive expansionist policies.
• Opposition within the U.S. led by Whigs who viewed the war as unjust.
• Abraham Lincoln's Spot Resolutions challenged the justification of the war.
• Henry David Thoreau's essay "Civil Disobedience" was written as a protest against the war.

Treaty and Outcome

• Treaty of Guadalupe Hidalgo signed on February 2, 1848.
• Mexico ceded territories that now include California, New Mexico, Arizona, Nevada, Utah, and parts of Colorado and Wyoming.
• The U.S. paid $15 million for these territories and assumed certain claims against Mexico.

Consequences

• Increased U.S. land by over 500,000 square miles.
• Contributed to rising tensions over slavery, impacting sectionalism in the U.S.
• The Wilmot Proviso, though never passed, highlighted the slavery debate in new territories.
• Many Civil War leaders gained experience, including Ulysses S. Grant and Robert E. Lee.

Legacy

• The war significantly altered U.S.-Mexico relations and had lasting effects on both countries.
• It reinforced stereotypes and left Mexico in a weakened state politically and socially.
• Set the stage for the Compromise of 1850 and future conflict leading to the American Civil War.