Important Dates from Exploration and Colonization By Mason.Sadler17 1519 Pineda maps Gulf of Mexico 1537 Cabeza de Vaca reports on explorations in Texas 1685 La Salle settle Fort St. Louis 1690 Established the mission San Francisco de los Tejas in East Texas. 1st mission in east Texas 1718 San Antonio founded 1719 East Texas missions are moved to San Antonio 1720 Mission San Jose is completed in San Antonio and other missions are built