The Mission San Antonio de Valero (the Alamo) was founded by Friar Antonio de San Buenaventura Olivares in May, 1718, near the tree-lined San Antonio River. Four more missions were built along the river during the next 13 years. All continued to operate until about 1794. In 1718, Don Martin de Alarcon, Captain General and Governor of the Province of Texas, established a military post here. San Antonio has been a military center ever since.

The Alamo is in the center of town. Here, from February 23 to March 6, 1836, Davy Crockett, Colonel James Bowie, Colonel William B. Travis, and 186 other Texans stood off General Antonio López de Santa Anna, dictator-president of Mexico, and his 5,000 men. Nearly every defender died in the battle. Their heroic stand was the inspiration for the famous Texas battle cry "Remember the Alamo!" Three months after the Alamo tragedy, San Antonio was almost deserted. Within a few years, however, it became a great Western outpost. In the 1840s, there was a heavy influx of Germans whose descendants still add to the city's cosmopolitan air. In the 1870s, new settlers, adventurers, and cowboys on long cattle drives made this a tough, hard-drinking, hard-fighting, gambling town. San Antonio has evolved into a modern, prosperous city, but it retains much of the flavor of its past.