Civil War at Alcatraz, su nps.gov, National Park Service, 19 marzo 2015. URL consultato il 7 marzo 2019.
«the army continued to work on Alcatraz throughout 1860 and 1861, expanding and improving the island’s existing fortifications. The military also used the island as a training ground for soldiers. New troops continually arrived on the island, underwent training, and departed for other assignments. With many new enlistees, the military personnel on Alcatraz increased to over 350 by the end of April 1861. The army slowly increased the number of men assigned to Alcatraz throughout the Civil War, reaching a high point of 433 men in early 1865. The army shipped most of these soldiers out to the Southwestern frontier; however, some were sent to battlefields in the East.»
