Most people know Alcatraz as the federal penitentiary that operated from 1934 until 1963. What they are surprised to learn is this was a U.S. Army fort starting in 1853. The military post was equipped with over 100 canons, 10,000 muskets and 150,000 cartridges of ammunition. The lighthouse was the first one located along the Pacific coast when it became functional in 1854. “The Rock” is now a major tourist attraction managed by the National Park Service.