The Mexican-American War (1846–1848) was a pivotal conflict in American history, driven by the United States’ desire to expand its territory under the belief in Manifest Destiny. The war began after the U.S. annexed Texas in 1845, a move that Mexico viewed as a violation of its sovereignty. Disputes over the Texas-Mexico border, with the U.S. claiming the Rio Grande as the boundary and Mexico asserting it was the Nueces River, escalated tensions. President James K. Polk, eager to acquire additional lands, sent American troops into disputed territory, leading to clashes and a declaration of war. U.S. forces, led by generals such as Zachary Taylor and Winfield Scott, achieved significant victories, including the capture of Mexico City. The war also saw the Bear Flag Revolt in California, where American settlers declared independence from Mexico.
The conflict ended with the Treaty of Guadalupe Hidalgo in 1848, a landmark agreement that reshaped the map of North America. Mexico ceded over 500,000 square miles of territory, encompassing modern-day California, Arizona, New Mexico, Utah, Nevada, and parts of Colorado and Wyoming. In exchange, the U.S. paid Mexico $15 million and assumed certain debts. While the war fulfilled the expansionist dreams of Manifest Destiny, it came with consequences. The acquisition of vast new territories intensified debates over slavery’s expansion, further dividing the nation. The Mexican-American War remains a defining chapter in U.S. history, marked by both territorial triumph and the seeds of future conflict.
Sources and Further Reading
- Library of Congress – The Mexican-American War
- National Park Service – The U.S.-Mexican War
- History.com – Mexican-American War
- PBS – U.S.-Mexican War
- Smithsonian Magazine – The Treaty of Guadalupe Hidalgo