Alcatraz Island the hands of Confederate sympathizers. Alcatraz, built as a "heavily fortified military site on the West Coast", formed a "triangle of defense" along with Fort Point and Lime Point, and ensured security to the bay. The island was also the site of the first operational lighthouse on the West Coast of the United States. Alcatraz never fired its guns offensively, though during the war it was used to imprison Confederate sympathizers and privateers on the west coast. Because of its isolation from the outside by the cold, strong, hazardous currents of the waters of San Francisco Bay, Alcatraz was used
Legends of Alcatraz 25 Scariest Places in the World". Alcatraz Citadel, also known as Fort Alcatraz, was the original military defense and prison on Alcatraz Island. The citadel was built in 1859 as a U.S. Army military defense, and began function as a war camp in 1861 and long-term military prison in 1868. During the American Civil War, the citadel and its batteries provided an important line of defense. The island continued to develop in the 1870s and 1880s, and in 1893, the first hospital on Alcatraz opened. A new upper prison was built in 1904, but after the citadel ceased function as