Battery McKinnon-Stotsenburg (1898)

Battery McKinnon-Stotsenburg began its life in 1898 as a single massive fortification, designed to guard the entrance to San Francisco Bay with a heavy array of sixteen 12-inch mortars. These mortars were powerful weapons that could lob massive projectiles in high arcs, allowing them to strike the deck of an enemy ship from above rather than just hitting its side. The battery's design was so significant that it provided a full 360 degrees of fire, meaning it could target vessels at sea, beaches, or even land forces approaching from any direction. In 1906, the military command decided to divide this expansive structure into two distinct batteries. The two eastern pits kept the name Battery Stotsenburg, while the two western pits were renamed Battery William McKinnon. Both names honored officers who had recently died in the line of duty during the Spanish-American War and the Philippine Insurrection. Captain John M. Stotsenburg was a decorated colonel killed in action in the Philippines, and Captain William McKinnon had served with distinction before dying on active duty in 1902. The battery’s operational life was defined by the rapid evolution of military technology. By 1917, the Army recognized the changing nature of coastal defense and transferred four of the mortars to a new fort at the city's southern edge. Eventually, the arrival of more modern weaponry and different tactical threats made these mortar pits obsolete. In 1943, during the height of the Second World War, the War Department ordered the metal components of the battery to be salvaged for scrap, effectively ending its role as an active defense installation. Today, the concrete pits remain as a quiet relic of an era when this coastline was the most heavily guarded perimeter in the region.