Military Period - The Post on Alcatraces & U.S. Disciplinary Barracks - 1850-1933
In 1850 Alcatraz was declared a military reservation by President Millard Fillmore, and by 1859 troops were permanently garrisoned at the post on Alcatraces for the defense of the Bay Area.
To learn more about Fort Alcatraz' role during the Civil War, please visit the Civil War at Alcatraz.
Bureau of Prisons Period - U.S. Penitentiary Alcatraz - 1934-1963
Alcatraz is most famous for the 29 years it operated as a U.S. penitentiary. During this complex period, over 1500 people were incarcerated on the island. Learn how Alcatraz evolved from an army post that contained an army prison into U.S. Penitentiary Alcatraz.
Indians of All Tribes Occupation - 1969-1971
In 1964, and again in 1969-1971, American Indian activists laid claim to Alcatraz Island. Their 19-month occupation would cause significant changes in federal policy and galvanize the Red Power movement. Learn more about the historic occupation by Indians of All Tribes, which marked its 50th anniversary in 2019.
Last updated: February 12, 2020