The massive concrete Alcatraz Cellhouse, completed in 1912, was originally designed to house military prisoners. When the prison became a federal penitentiary in 1934, the majority of the cellblocks were renovated with tool-proof steel bars, remotely operated doors, and other maximum-security technologies. A Block, however, was not remodeled; more than any other part of the cellhouse, it retains the traces of Alcatraz’s military past.
With its flat “strap iron” bars and keyed doors, A Block and the rest of the old military prison may have been less secure than the modern federal penitentiary, but the original “Disciplinary Barracks” was a no less forbidding environment. Six cells on the top tier of A Block were used for solitary confinement; outfitted with solid doors punctured by a few ventilation holes, they were precursors to the infamous isolation cells of D Block. Down below, steps led from the ground floor of A Block to the basement of the Citadel, the remnants of the original fort built in the 1850s. In the military prison period and in the early years of the federal penitentiary, parts of the basement were used for isolation; these dank, dark spaces earned the nickname “the Dungeon.”
Among the inmates who became all too familiar with the military prison’s lower depths was Philip Grosser, an anarchist and World War I conscientious objector, one of a number of men who were imprisoned on Alcatraz for refusing to serve in the military on political or religious grounds. Grosser spent 18 months on Alcatraz, including long stretches in solitary confinement, and later wrote a scathing report on prison conditions. He vividly described his experiences in the Dungeon and in the vestibule doors, 12-by-23-inch cages attached to the regular cell doors. Forced to stand in one of these “coffin cages” for eight hours a day, Grosser called the device a “veritable iron straight jacket.” The vestibule doors were removed after 1920, but the hinges that are believed to have held them are still attached to some cell doors in A Block.
After Alcatraz became a federal prison, A Block was rarely used to confine inmates, except on rare occasions when prisoners needed to be completely separated from the general population; instead, the space was used for offices and storage. At least some of the federal prisoners who saw the inside of A Block came there voluntarily: cells equipped with typewriters and legal reference books gave prisoners a place to work on their legal cases or type correspondence, keeping some connection to life on the outside.