From fort to prison

The prison was originally a defence fort on Alcatraz Island, about 22 acres in size and located about 2 kilometres offshore from the city of San Francisco.

In 1846, the US gained control of the island after John C Frémont, then military governor of California, bought it from naturalised Mexican citizen Francis Temple in the name of the federal government.

Four years later, then US President Millard Fillmore recognised the island’s strategic military value following the Mexican–American War (1846-1848), and the onset of the California Gold Rush (1848–1855). He signed an Executive Order reserving lands around San Francisco Bay, including Alcatraz, for “public purposes.”

The cell of a prisoner permitted to make oil paintings at Alcatraz Federal Penitentiary on Alcatraz Island in San Francisco Bay, California, March 16, 1956. (AP Photo, File)

A fort was thus constructed on the island, with the initial structure completed in 1858. Around 100 cannons and military men were stationed. The West Coast’s first operational lighthouse was also built on Alcatraz in 1854.

However, over time, the island’s necessity for defence purposes diminished (Alcatraz never fired its guns in combat). As it was isolated from the mainland due to the strong ocean currents and cold Pacific waters, the island began to be seen as a secure detention centre. By the late 1850s, the Alcatraz Fort was being used as a military prison to house various military personnel, including those convicted of offences by court-martial, deserters, and those deemed a security risk.

During the Civil War (1861-1865), the prison also housed Confederate prisoners of war as well as private citizens accused of treason or being Confederate sympathisers. With the number of inmates increasing throughout the war, additional cells were constructed.

After the Civil War, the prisoner demographics grew to include Native American prisoners from the American Indian Wars (1609-1924), which were fought to displace Indigenous people from their ancestral lands and bring in White settlers.

The prisoner population kept rising in the following years, especially after the Spanish-American War broke out in 1898, bringing the number to around 450.

To accommodate the inmates, the military decided to revamp the fort entirely, and in 1907, the structure was formally designated a US military prison. The reconstruction happened between 1910 and 1912, and the new prison was renamed “the Pacific Branch, US Disciplinary Barracks for the US Army”, and was more popularly known as The Rock by those who worked or were incarcerated there, according to a report by the US General Services Administration (GSA).

Morphing into Devil’s Island

Alcatraz stopped operating as a military prison in 1933 due to the increasing maintenance costs. After the prison shut down, the military left the island, and it was acquired by the US Department of Justice, which turned it into a federal prison.

Operated by the Federal Bureau of Prisons, Alcatraz was modernised and fortified in 1934, becoming America’s first maximum-security civilian penitentiary. It was done in the wake of “prohibition, the Great Depression, and the advent of organised crime”, which had led “citizens and politicians alike to demand a prison that could securely house dangerous and notorious crime figures,” according to The Social History of Crime and Punishment in America: An Encyclopedia (2012), edited by Wilbur R Miller.

A view from a helicopter of Alcatraz Prison, a National Parks site located on Alcatraz Island in San Francisco Bay in San Francisco, California, U.S. May 5, 2025. (REUTERS/Fred Greaves)

The facility housed notorious criminals such as gangster Al “Scarface” Capone, who was convicted of tax evasion. During his reign as a crime boss between 1925 and 1933, Capone ran “an empire of crime” in Chicago that was based on “gambling, prostitution, bootlegging, bribery, narcotics trafficking, robbery, and murder,” according to the FBI website. Alvin “Creepy” Karpis, who led a criminal gang in the 1930s and was the FBI’s first “Public Enemy,” served more than 25 years in Alcatraz.

The most famous prisoner at the facility was Alaskan murderer Robert “Birdman” Stroud. He was convicted of manslaughter and sent to a penitentiary in McNeil Island, Washington, in 1909. However, he attacked another inmate, leading to his transfer to another prison, where Stroud murdered a security guard. He came to Alcatraz in 1942 and spent the next 17 years there. Over the years, Stroud developed an interest in birds and went on to become an expert ornithologist.

Prisoners typically arrived in Alcatraz in handcuffs and ankle shackles. Their daily life was harsh, and they were given only four rights — food, clothing, shelter and medical care. Other privileges, such as corresponding with family members and recreational activities, had to be earned through hard work. “Punishments for bad behaviour included hard labour and lock-downs in solitary confinement, restricted to bread and water,” according to the website of the National Park Service, which currently operates Alcatraz as a tourist destination.

As a federal prison, there were 14 escape attempts by 34 prisoners at Alcatraz. Nearly all prisoners who tried to escape were believed to have drowned or were shot dead by guards or recaptured. The 1979 film Escape from Alcatraz, starring Clint Eastwood, showed the real escape attempt of prisoners Frank Morris and brothers Clarence and John Anglin (they were never seen again after their escape).

Closure and later years

Much like the US military, the Federal Bureau of Prisons found it extremely expensive to run the Alcatraz prison. A 1959 report found that its operation costs were three times those of a comparable prison. “It costs $10 per prisoner per day compared to $3 in other prisons,” the GSA said, citing the report.

Another issue was that the perpetual salt exposure due to the surrounding waters corroded its structures. An estimate suggested that it would cost $5 million to repair the damage. These factors eventually led to the prison’s closure on March 21, 1963.

For years, no significant activity took place on the island until 1969, when a group of Native American students, known as “Indians of All Tribes”, arrived there by boat. They occupied the island in a bid to raise awareness about the numerous social and economic plights faced by Indigenous populations in the US. The students remained there for about 19 months, after which federal marshals moved in and forcibly removed them in June 1971.

The next year, the island became a national recreation area under the management of the National Park Service. It opened for tourists in 1973.