Complex sentence: Established in 1722 on Matagorda Bay near La Salle's Fort Saint Louis on Garcitas Creek, the mission and complementing presidio (fort) was intended to secure the Texas coastline from the French and to gather the local Cocos, Copanes, and Cujanes.
Split into simpler sentences: Established in 1722 on Matagorda Bay near La Salle's Fort Saint Louis on Garcitas Creek. The mission and complementing presidio (fort) was intended to secure the Texas coastline from the French and to gather the local Cocos, Copanes, and Cujanes.