Mexican-American War Facts

Also Known As

The Mexican-American War is also known as the U.S.-Mexican War and the Mexican War.

The Mexican-American War lasted from April 25, 1846 until February 2, 1848.
The Mexican-American War was fought on four fronts, Northern Mexico, New Mexico, California, and Central Mexico.

A primary cause of the Mexican-American War was a border dispute between the United States and Mexico along the Rio Grande and Nueces rivers in Texas.
A primary cause of the Mexican-American War was U.S. President James K. Polk’s firm belief that the United States was destined to expand its borders to the Pacific Ocean. Expansionist journalists adopted his stance and popularized the concept as America’s “Manifest Destiny.”

Primary American military commanders during the Mexican-American War were General Zachary Taylor, General Winfield Scott, Lieutenant Colonel John C. Frémont, Colonel Stephen W. Kearny, Commodore John D. Sloat, Commodore Robert F. Stockton, and Brigadier General John E. Wool.

Primary Mexican military commanders during the Mexican-American War were Antonio López de Santa Anna, General Mariano Arista, General Pedro de Ampudia, Captain José María Flores, and General Nicolás Bravo.

Significant battles fought on the Texas-Northern Mexico Front of the Mexican-American War included, the Battle of Palo Alto (May 8, 1846), the Battle of Resaca de la Palma (May 9, 1846), the Battle of Monterrey (September 21-24, 1846), and the Battle of Buena Vista (February 22–23, 1847).
Significant battles fought on the California Front of the Mexican-American War included, the Battle of Chino (September 26–27, 1846), the Battle of Dominguez Rancho (October 7, 1846), the Battle of Rio San Gabriel (January 8, 1847), and the Battle of La Mesa (January 9, 1847).
Significant battles fought on the New Mexico Front of the Mexican-American War included the Battle of Cañoncito (August 15, 1846).
Significant battles fought on the Central Mexico Front of the Mexican-American War included, the Siege of Veracruz (March 9–29, 1847), the Battle of Cerro Gordo (April 18, 1847), the Battle of Contreras (August 19-20, 1847), the Battle of Churubusco (August 21, 1847), the Battle of Molina del Rey, (September 8, 1847), the Battle of Chapultepec Castle (September 12-13, 1847), and the Siege of Puebla (September 13-October 12, 1847).

American armies that fought in the Mexican-American War were the Army of Occupation, Army of the Center, Army of the West, and the Army of Invasion.

United States casualties during the Mexican-American War totaled about 17,000 (13,000 dead and 4,000 wounded). Of the deaths, roughly 1,800 military personnel died in combat. The others died from sickness and disease.
Mexican casualties during the Mexican-American War totaled about 25,000, including possibly 1,000 civilians.

On February 2, 1848 representatives from the United States and Mexico signed the Treaty of Guadalupe Hidalgo, which concluded the Mexican-American War.
The Treaty of Guadalupe Hidalgo established the Rio Grande River as the southernmost border between Mexico and the United States. It also required Mexico to cede California, Arizona, New Mexico, and portions of Utah, Nevada, and Colorado to the United States, in return for a payment of $15 million.
The U.S. Senate ratified the Treaty of Guadalupe Hidalgo on March 10, 1848.
The Mexican Congress ratified the Treaty of Guadalupe Hidalgo on May 25, 1848.

Zachery Taylor’s military successes in Northern Mexico during the Mexican-American War buoyed his political ambitions, enhanced his popularity, and propelled him to victory in the 1848 U.S. presidential election.
On the home front in the United States, the Mexican-American War crystallized and polarized sectional differences over the extension of slavery in the United States.
The Mexican-American War was a training ground for numerous general officers who fought on both sides during the American Civil War.