Fort Point occupies the narrow entrance to San Francisco Bay, a position first fortified by Spain in 1794 with the adobe Castillo de San Joaquín. After Mexico gained independence, the small work deteriorated and was abandoned. United States forces occupied the site during the war with Mexico, and the conquest of California placed the Golden Gate under American control just before the gold rush transformed San Francisco into a major port.

The U.S. Army began the present fort in 1853 as part of a national system of masonry coastal defenses. Engineers cut down the high bluff so cannon on the lowest tier could fire close to water level. Mexican and Chilean laborers, skilled masons, military personnel, and civilian contractors raised millions of bricks into a four-tier structure containing casemates, magazines, quarters, and a courtyard. The fort was designed for more than one hundred heavy guns, though it never received its full intended armament.

Construction ended as the Civil War began. California remained in the Union, and troops guarded Fort Point against Confederate raiders and possible foreign intervention. No enemy attacked the Golden Gate, but the garrison’s vigilance protected the mint, harbor, shipyards, and supply routes linking the Pacific economy to the Union war effort. The Confederate cruiser Shenandoah considered an attack in 1865 but learned that the war had ended before reaching San Francisco.

Rifled artillery had meanwhile demonstrated that brick forts were vulnerable. Fort Point never fought the kind of bombardment that shattered Fort Pulaski, but the lesson made its design obsolete. The Army withdrew its regular garrison and later installed newer concrete batteries on higher ground. A seawall completed in 1869 protected the fort from waves. It served intermittently for barracks, storage, and training, and soldiers returned during the Second World War to guard the minefield and antisubmarine net across the Golden Gate.

Plans for the Golden Gate Bridge initially threatened demolition. Chief engineer Joseph Strauss valued the masonry and redesigned the southern approach with an arch spanning the fort. Preservation advocates renewed their campaign after the war, and Congress created Fort Point National Historic Site in 1970.

The fort now records Spanish, Mexican, and American claims to the bay, Gold Rush engineering, Civil War mobilization, and changing weapons technology. Its famous location beneath the bridge should not reduce it to a scenic backdrop. The surviving casemates embody labor, military discipline, immigration, and the enormous resources devoted to an attack that never came. Preservation must contend with salt air, moisture, seismic risk, and bridge vibration while keeping the fort accessible as both architecture and evidence of nineteenth-century national expansion.

The fort’s later survival was never automatic. Army plans, changing harbor defenses, and construction of the Golden Gate Bridge all threatened or altered its setting. Chief engineer Joseph Strauss redesigned the bridge approach so the fort could remain beneath the southern anchorage. During the Second World War it served storage and training purposes rather than frontline coastal defense. Preservation advocates then argued that it embodied the engineering and military history of San Francisco Bay. Congress established Fort Point National Historic Site in 1970. Today seismic risk, salt air, moisture, and heavy use require constant conservation, while interpretation places the impressive brickwork within histories of conquest, wartime anxiety, immigrant labor, and the displacement of Indigenous peoples.