The Mexican War-- Proving Ground for Civil War Generals.

In the Mexican War the U.S. military used on a three-pronged strategy signed to seize control of northern Mexico and force an early peace. Two American armies moved south from Texas, while a third force traveled west to Sante Fe, New Mexico and then to California. In a series of battles at Palo Alto and Resaca de Palma, the army of General Zachary Taylor defeated the Mexican forces and moved south.

In July and August of 1846, the United States Navy seized Monterey and Los Angeles California. In September 1846, Taylor's army fought General Ampudia's forces for control of the northern Mexican city of Monterey in a three-day battle. Following the capture of the city by the Americans, there was a temporary truce which enabled both armies to recover. During this time, former President Santa Anna returned to Mexico from exile and raised a new army of over 20,000 men. Despite defeat in several major battles, the Mexican government refused to make peace.

It became apparent to the Americans that only a complete battlefield victory would end the war. Continued fighting in the dry deserts of northern Mexico convinced the United States that an overland expedition to capture the enemy capitol at Mexico City, would be hazardous and difficult. Because of this General Winfield Scott proposed what would become the largest amphibious landing in history to that time, which included a campaign to seize Mexico City. In March 1847, General Scott landed with an army of 12,000 men on the beaches near Vera Cruz, Mexico. From this point, from March to August, Scott and Santa Anna fought a series of battles from the coast inland toward Mexico City. The more important battles include the Battles of : Cerro Gordo, Contreras, Churubusco, Molino del Rey and Chapultepec. Finally, in September, the Americans entered Mexico City. There was some resistance but by mid-October, the U.S. had full control.

Following the city's occupation, Santa Anna resigned the presidency but retained command of his army. He attempted to continue military operations against the Americans, but his troops, refused to fight. His government soon asked for his military resignation. On February 2, 1848, The Treaty of Guadalupe Hidalgo was signed. The treaty called for the annexation of the northern portions of Mexico to the United States. In return, the U.S. agreed to pay $15 million to Mexico as compensation for the seized territory. This ended the Mexican War.