Alcatraz Citadel having some 111 cannons encircling the island at peak, and was also used as a war camp. During the Civil War, the defense establishment at Alcatraz Citadel had the onerous task to defuse the possibility of any local war between the Union and Confederate supporters who were both part of the population of California, and to protect San Francisco. Ammunition in the form of 10,000 muskets and 150,000 cartridges was supplied to the fort, which made the Fort Alcatraz and the island most impregnable and thus leaving any plans of the Confederate soldiers of taking control of the San Francisco
Alcatraz Wharf and sank in deep water off the wharf in the early 1910s. Her crew of forty-two men escaped by jumping into the bay and swimming ashore. Seismic rehabilitation of the wharf occurred in the early 2000s. The retrofit to the existing wharf and its facilities consisted of concrete demolition, excavation, and installation of tiebacks. Reinforced steel and concrete were added to a new deck. Work was also done on the deteriorated piles under the wharf deck.David Finney is the youngest person to swim the South End Rowing Club Alcatraz Swim when he swam it in 2015 at ten years old.