Alcatraz Citadel Bay and California State could be taken under its fold was thwarted. Alcatraz was officially designated as a military prison on August 27, 1861. In March 1863, when there was a threat that the San Francisco Bay would be captured by the Confederates, the schooner, which was to carry out the operation set sail; the U.S. Navy prevented the schooner from moving out and captured the crew along with ammunition and 15 confederates who were hiding in the galleys of the ship. Consequent to this, the importance of Alcatraz increased, more and more confederates and civilians were arrested for reasons
Alcatraz Island self-determination, in part as a result of the publicity and awareness created by the occupation. The occupation ended on June 11, 1971. The entire Alcatraz Island was listed on the National Register of Historic Places in 1976, and was further declared a National Historic Landmark in 1986. In 1993, the National Park Service published a plan entitled "Alcatraz Development Concept and Environmental Assessment." This plan, approved in 1980, doubled the amount of Alcatraz accessible to the public to enable visitors to enjoy its scenery and bird, marine, and animal life. Today, American Indigenous groups, such as the International Indian Treaty