What were presidios built for during the Spanish colonial period?

During the Spanish colonial period, presidios were primarily constructed to protect missionaries and settlers. These fortified military posts were established in areas where Spanish missions and settlements were present, serving as a defense mechanism against potential threats from Indigenous populations as well as rival colonial powers. By providing military support and a secure environment, presidios played a crucial role in ensuring the safety of the missionaries who aimed to convert local Indigenous peoples to Christianity and helped stabilize the growing Spanish presence in the region.

While trade centers and homes for military leaders may have been present in these areas, the core function of presidios was defense, thus emphasizing their primary purpose in securing the missions and settlements. Detering foreign invasions was also a consideration, but it was always secondary to the immediate need for the safety of the community they protected.