Portsmouth Naval Prison

Portsmouth Naval Prison is a former U.S. Navy and Marine Corps prison on the grounds of the Portsmouth Naval Shipyard (PNS) in Kittery, Maine. The building has the appearance of a castle. The reinforced concrete naval prison was occupied from 1908 until 1974.

The island site was first used in 1775 during the Revolution when the New Hampshire militia, commanded by General John Sullivan, constructed an earthwork defense called Fort Sullivan atop the bluff. In conjunction with Fort Washington across the Piscataqua River on Pierce Island, it guarded the channel to Portsmouth. The militia withdrew about three years later. The fort was reactivated for the War of 1812 in 1814. In 1861, it was rebuilt with eleven 8-inch Rodman guns to protect Portsmouth against attacks by the Confederate navy. After 1866, Fort Sullivan was dismantled. Camp Long, named for Secretary of the Navy John Long, was erected nearby during the Spanish–American War. From 11 July to mid-September in 1898, the housed 1,612 Spanish prisoners, including Admiral Pascual Cervera, until returned to Spain.

When Camp Long was dismantled in 1901, the site became available for a naval prison. Constructed between 1905 and 1908, the brig was modeled after Alcatraz, set on an island with tidal currents to deter escape. Colonel Kelton of the Marine Corps was in command when the first Navy prisoners arrived in 1908. It would eventually house Marine inmates as well. The central crenellated tower, roofed in copper, was erected in 1912. Lieutenant Commander Thomas Osbourne assumed command in 1917. Called "the Father of Naval Corrections," Osbourne and 2 others went undercover in the prison to see what changes needed to be made, including living conditions. During World War I, the prison housed wartime convicts, reaching a maximum of 2,295 in 1918. Two wings were added—in 1942 the northeast wing, and in 1943 the unornamented southwest wing, dubbed "the Fortress," which rises sheer beside the rocky shore. Maximum occupancy reached 3,088 in 1945.

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