During the Mexican-American War, the American army was divided into two, the US Army and the militia, which is composed of militiamen. The US Army was the American's national army, while the militia is an army of several states. They had a total army of 116,119 men and a navy of 12,319 men (1846-1848). During the war, they were better equipped and better led, which gave them a big advantage. When the war ended, the total losses were 13,283 men dead and 4,152 men wounded.
Zachary Taylor was a general in the US Army. He led his troops through various victories, including the occupations of Matamoras, Monterrey, Saltville and Victoria, and he also defeated the Mexican troops of Mexico City when the US armies almost lost there. Later he was elected president in 1848.
Alexander W. Doniphan, a colonel, led 850 troops through battles like the Battle of Sacramento (1847), and he occupied an important Mexican city of Chihuahua.
General Winfried Scott, highest ranking of the US army at that time, used only 10,000 men and won Vera Cruz, Contreras, Churubusco, the battle at...