What was built to protect the missions that were established by the Spanish?

Answer 1

A presidio is a fortified base established by the Spanish in North America between the sixteenth and nineteenth centuries. The fortresses were built to protect against pirates, hostile native Americans and enemy colonists. Other presidios were held by Spain in the sixteenth and seventeenth centuries, in Italy, on Elba and in North Africa. Later, with independence, the Mexicans garrisoned the Spanish presidios on the northern frontier and followed the same pattern in unsettled frontier regions like the Presidio de Sonoma, at Sonoma, California and the Presidio de Calabasas, in Arizona. A short distance outside a presidio, would be a rancho del rey, or king's farm, a tract of land assigned to it to furnish pasturage to the horses and other beasts of burden of the garrison