The Alamo was the San Antonio mission that became the site of the famous 1836 Battle of the Alamo.
Originally called Misión San Antonio de Valero, the Spanish mission was founded in the eighteenth century. After it was secularized and later used as a military post, the compound became known as the Alamo, probably after a Spanish military unit or nearby cottonwood trees.
Mexican forces under Antonio López de Santa Anna besieged the mission from February 23 to March 6, 1836. The Texian defenders, including James Bowie, William B. Travis, and Davy Crockett, were defeated, but the battle became a rallying point for the Texas Revolution. The phrase “Remember the Alamo!” helped inspire Texian forces before their victory at San Jacinto on April 21.
The Alamo was a mission compound, not originally a fortress built for the battle. It is now a museum and part of the San Antonio Missions UNESCO World Heritage Site.