From 11 July to mid-September in 1898, the stockade housed 1,612 Spanish prisoners, including Admiral Pascual Cervera, until returned to Spain.

Called "the Father of Naval Corrections," Osborne and two others went undercover in the prison to see what changes needed to be made, including living conditions.

By 1921 President Warren G. Harding had appointed a new Secretary of the Navy, who promptly ended Osborne's Mutual Welfare League program for prisoners at Portsmouth.

The interrogations were classified at the time because of potential military value of information collected about German submarine, jet aircraft, ballistic missile, guided bomb, and nuclear weapons technology.

Kapitänleutnant Friedrich Steinhoff was slapped by a large, husky Marine guard until his face was swollen and bleeding, and died in a Charles Street Jail cell after two days of interrogation.

Scattered documents and clothing were perceived as fire and access hazards while the U-boats awaited inspection by shipyard engineers.

Decorations and personal possessions taken from U-boat crewmen were retained as souvenirs rather than returned to prisoners of war as required by the Geneva Conventions.

During warmer months, it was not uncommon for boats navigating the river to hear shouts and whistles coming from within barred windows of "the Fortress."

Male convicts from all the services sentenced to punitive discharge and incarceration longer than seven years are confined at the third tier—the maximum-security U.S. Disciplinary Barracks at Fort Leavenworth, Kansas.

The Portsmouth Naval Prison, built to be a modern correctional facility for a navy which had once disciplined by flogging and capital punishment, was rendered obsolete.

In the 1973 movie The Last Detail, seaman Larry Meadows (Randy Quaid) is escorted by petty officers Billy "Badass" Buddusky (Jack Nicholson) and Mule Mulhall (Otis Young) to the Portsmouth Naval Prison.

They decide to show the naive sailor the time of his life before arriving on Seavey's Island (where another location substitutes for the actual brig).

But plans to adapt the prison were halted a month after Sawtelle's death in 2000, and abandoned altogether after military base security was tightened following the September 11 attacks.