During the Mexican-American War, U.S. forces under General Winfield Scott invade Mexico three miles south of Vera Cruz. Encountering little resistance from the Mexicans massed in the fortified city of Vera Cruz, by nightfall the last of Scott's 10,000 men came ashore without the loss of a single life. It was the largest amphibious landing in U.S. history and not surpassed until World War II.
The Mexican-American War began with a dispute over the U.S. government's 1845 annexation of Texas. In January 1846, President James K. Polk, a strong advocate of westward expansion, ordered General Zachary Taylor to occupy disputed territory between the Nueces and Rio Grande Rivers. Mexican troops attacked Taylor's forces, and on May 13, 1846, Congress approved a declaration of war against Mexico. In March 1847, General Scott's forces landed near Vera Cruz, and by March 29, with very few casualties, the Americans had taken the fortified city and its massive fortress, San Juan de Ulua. In April, Scott began his devastating march to Mexico City, which ended on September 14, when U.S. forces entered the Mexican capital and raised the American flag over the Hall of Montezuma.
In February 1848, representatives from the United States and Mexico signed the Treaty of Guadalupe Hidalgo, formally ending the Mexican War, recognizing Texas as part of the United States and extending the boundaries of the United States west to the Pacific Ocean.