The Alamo began in 1718 as Mission San Antonio de Valero. Governor Martin de Alarcon formally entrusted it to Father Antonio de San Buenaventura y Olivares on May 1. A hurricane destroyed the first buildings, so the mission moved to its present site in 1724. It was secularized in 1793 and soon abandoned.
Mexican forces besieged the Alamo for 13 days beginning February 23, 1836, and the final assault came on March 6. They stayed about two months, then left on May 24, tearing down many walls and leaving the chapel in ruins.
The U.S. Army used part of the compound as a supply depot from 1846 to 1876. The Catholic Church sold the chapel to the State of Texas for $20,000 in 1883, and in 1905 the legislature bought the rest and made the Daughters of the Republic of Texas its custodian. It became a UNESCO World Heritage Site on July 5, 2015.