The Battle of the Alamo (February 23 – March 6, 1836) was a pivotal event in the Texas Revolution. Following a 13-day siege, Mexican troops under President General Antonio López de Santa Anna launched an assault on the Alamo Mission near San Antonio de Béxar (modern-day San Antonio, Texas, USA). All but two of the Texian defenders were killed. Santa Anna's perceived cruelty during the battle inspired many Texians—both Texas settlers and adventurers from the United States-to join the Texian Army. Buoyed by a desire for revenge, the Texians defeated the Mexican Army at the Battle of San Jacinto, on April 21, 1836, ending the revolution.
Several months prior, Texians had driven all Mexican troops out of Mexican Texas. Approximately 100 Texians were then garrisoned at the Alamo. The Texian force grew slightly with the arrival of reinforcements led by eventual Alamo co-commanders James Bowie and William B. Travis. On February 23, approximately 1,500 Mexican troops marched into San Antonio de Béxar as the first step in a campaign to re-take Texas. For the next 12 days the two armies engaged in several skirmishes with minimal casualties. Aware that his garrison could not withstand an attack by such a large force, Travis wrote multiple letters pleading for more men and supplies, but fewer than 100 reinforcements arrived.