Fearing that someone would murder him in the recreation yard, Al Capone received permission to spend recreational time practicing his banjo in the shower room. Today, visitors and employees still report banjo music coming from the showers.

D-Block housed the worst inmates, and six cells at its end were designated "The Hole", where misbehaving prisoners would be sent for periods of sometimes brutal punishment.

There were no female correctional officers or prisoners on Alcatraz. Women prisoners could not be declared "incorrigible" until 1969, six years after the closure of Alcatraz. The only females on the island were visitors and the correctional officers' wives and daughters.

On November 13, 1937, Wutke became the first prisoner on Alcatraz during its period as a penitentiary to successfully commit suicide, fatally slicing through his jugular vein with the blade from a pencil sharpener.

During World War I, the prison held conscientious objectors, including Philip Grosser, who wrote a pamphlet entitled Uncle Sam's Devil's Island about his experiences.

Depression-era gangster Alvin Karpis, nicknamed "Creepy" for his sinister smile, served 26 years at Alcatraz before he was transferred to McNeil Island Penitentiary in Washington state.

The Battle of Alcatraz, which lasted from May 2 to 4, 1946, was the result of an unsuccessful escape attempt by armed convicts. Two Federal Bureau of Prisons officers were killed along with three of the perpetrators. Fourteen other officers and one uninvolved convict were also injured. Two of the surviving perpetrators were later executed in 1948 for their roles.

Beginning in November 1969, the island was occupied for more than 19 months by a group of Native Americans from San Francisco, who were part of a wave of Native American activists organizing public protests across the US through the 1970s. They claimed Alcatraz Island by the "Right of Discovery", as indigenous peoples knew it thousands of years before any Europeans had come to North America.

The parade grounds, carved from the hillside during the late 19th century and covered with rubble since the government demolished guard housing in 1971, have become a habitat and breeding ground for black-crowned night herons, western gulls, slender salamanders, and deer mice.

One of San Francisco's major tourist attractions, Alcatraz draws some 1.7 million visitors annually.