Bastion by the Bay: The Presidio of San Francisco, from Outpost of Empire to Magnificent Park

Since ancient times societies have employed outposts to secure new frontiers. The Presidio of San Francisco, founded in 1776, offers a classic case study of this phenomenon. Under the flags of Spain, Mexico, and the United States, this bastion by the bay stood guard over a major port that evolved into the storied city by the Golden Gate.

During the early phases of the presidio’s precarious existence, the Spanish erected a less-than-imposing fort and a pair of tiny artillery emplacements arm...