A chain of five missions established along the San Antonio River
in the 18th century became the largest concentration of Catholic missions in
North America. Built primarily to expand Spanish New World influence northward
from Mexico, the missions also served to introduce native inhabitants into
Spanish society.
Four of the missions (San Jose, San Juan, Concepcion, and Espada) were
originally founded in East Texas. As the East Texas missions succumbed to
drought, malaria, and French incursions, however, they were relocated to San
Antonio.
The missions flourished during the middle of the 18th century, but later declined due to inadequate military support, disease, and increased hostilities with Apaches and Comanches.