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
Escape from Alcatraz (triathlon) foot race, but by making it an out-and-back run rather than a one-way course, became known as a "Double Dipsea". The course has remained the same over the years and celebrated its 35th anniversary in 2015. Participants are limited to members of the Dolphin Club and The South End Club. The Dolphin Club is the host and sponsor of the event. The annual public Escape from Alcatraz triathlon, organized by IMG, now takes place in early June. The current course consists of a swim starting near Alcatraz Island, a run from the bay to the transition zone at Marina Green,