Historical Site dedicated to The Alamo. The Battle of the Alamo (February 23 – March 6, 1836) was a pivotal event and military engagement in the Texas Revolution. Following a 13-day siege, Mexican troops under President General Antonio López de Santa Anna reclaimed the Alamo Mission near San Antonio de Béxar (modern-day San Antonio, Texas, United States), killing most of the occupants. Santa Anna's refusal to take prisoners during the battle inspired many Texians and Tejanos to join the Texian Army. Motivated by a desire for revenge, as well as their written desire to preserve a border open to immigration and the importation and practice of slavery, the Texians defeated the Mexican Army at the Battle of San Jacinto, on April 21, 1836, ending the conquering of the Mexican state of Coahuila y Tejas by the newly formed Republic of Texas.