Alcatraz Federal Penitentiary

United States Penitentiary, Alcatraz Island, also known simply as Alcatraz (English: , Spanish: [alkatas] "the gannet") or The Rock, was a maximum security federal prison on Alcatraz Island, 1.25 miles (2.01 km) off the coast of San Francisco, California, United States. The site of a fort since the 1850s, the main prison building was built from 1910 to 1912 as a U.S. Army military prison. The United States Department of Justice acquired the United States Disciplinary Barracks, Pacific Branch, on Alcatraz on October 12, 1933. The island became adapted and used as a prison of the Federal Bureau of Prisons in August 1934 after the buildings were modernized and security increased. Given this high security and the island's location in the cold waters and strong currents of San Francisco Bay, prison operators believed Alcatraz to be escape-proof and America's most secure prison. The three-story cellhouse included the four main cell blocks – A-block to D-block – the warden's office, visitation room, the library, and the barber shop. The prison cells typically measured 9 feet (2.7 m) by 5 ft (1.5 m) and 7 ft (2.1 m) high. The cells were primitive and lacked privacy. They were furnished with a bed, desk, washbasin, a toilet on the back wall, and few items other than a blanket. D-Block housed the worst inmates, and six cells at its end were designated "The Hole". Prisoners with behavioral problems were sent to these for periods of often brutal punishment. The dining hall and kitchen extended from the main building. Prisoners and staff ate three meals a day together. Alcatraz Hospital was located above the dining hall. Prison corridors were named after major U.S. streets, such as Broadway and Michigan Avenue, of New York City and Chicago, respectively. Working at the prison was considered a privilege for inmates. Those who earned privileges were employed in the Model Industries Building and New Industries Building during the day, actively involved in providing for the military in jobs such as sewing and woodwork, and performing maintenance and laundry chores. The prison closed in 1963. Alcatraz reopened as a public museum. From 1969 to 1971, the island and prison were occupied by Native Americans. It is one of San Francisco's major tourist attractions, attracting some 1.5 million visitors annually. Now operated by the National Park Service's Golden Gate National Recreation Area, the former prison is being restored and maintained.

The main cellhouse was built incorporating some parts of Fort Alcatraz's citadel, a partially fortified barracks from 1859 that was used as a jail during the Civil War for alleged Confederate sympathizers. C. L. Weller, the Chairman of the State Democratic Committee and brother of California governor John B. Weller, was one of the first prisoners housed there. A new cellhouse was built from 1910 to 1912 on a budget of $250,000, equivalent to $8,340,517 in 2025. Upon completion, the 500-foot (150 m) long concrete building was reputedly the longest concrete building in the world at the time. This building was modernized in 1933 and 1934 and became the main cellhouse of the federal penitentiary. The building closed in 1963. When the new concrete prison was built, many materials were reused in its construction. Iron staircases in the interior and the cellhouse door near the barber's shop at the end of A-block were retained from the old citadel. Massive granite blocks originally used as gun mounts were reused as the wharf's bulkheads and retaining walls. Many of the old cell bars were used to reinforce the walls; many placed near the edge were subject to erosion from the salt air and wind over the years.

Prison data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).