Alcatraz Island Engineers began fortifying the island, work which continued until 1858, eventuating in Fortress Alcatraz. The island's first garrison at Camp Alcatraz, numbering about 200 soldiers and 11 cannons, arrived at the end of that year. When the American Civil War broke out in 1861, the island mounted 85 cannons (increased to 105 cannons by 1866) in casemates around its perimeter, though the small size of the garrison meant only a fraction of the guns could be used at one time. At this time it also served as the San Francisco Arsenal for storage of firearms to prevent them falling into
Alcatraz Island August 1934. Alcatraz was designed to hold prisoners who continuously caused trouble at other federal prisons. At 9:40 am on August 11, 1934, the first batch of 137 prisoners arrived at Alcatraz, arriving by railroad from the United States Penitentiary in Leavenworth, Kansas at Santa Venetia, California, before being escorted to Alcatraz, handcuffed in high security coaches and guarded by some 60 special FBI agents, U.S. Marshals and railway security officials. Most of the prisoners were notorious bank robbers and murderers. The prison initially had a staff of 155, including the first warden James A. Johnston and associate warden J.