The Battle of Veracruz was a 20-day siege of the key Mexican beachhead seaport of Veracruz, lasting from March 9-29th in 1847. It began with the first large-scale amphibious assault conducted by United States military forces, and ended with the surrender and occupation of the city. The Battle of Buena Vista (February 23, 1847), also known as the Battle of Angostura, saw the US Army use artillery to repulse the much larger Mexican army in the Mexican-American War. The battle was the last major battle in northern Mexico. It was Taylor's greatest victory of the war and helped him win election as President of the United States in 1848. The Mexican-American War was an armed conflict between the United States of America and Mexico from 1846 to 1848 in the wake of the 1845 US annexation of Texas. Combat operations lasted from spring 1846 to fall 1847.