2-324-185 - Curt Teich Postcard Archives/Heritage Images

Old Fort Jefferson on the Dry Tortugas, near Key West, Florida, USA, 1940. Postcard. Exterior view of the fort. A bridge crosses a moat to the entrance. The ocean is visible beyond the fort. The Dry Tortugas are a group of islands off the Florida Keys. They occupy a stategic position able to threaten shipping in the Gulf of Mexico and as a result, in 1846, the US government began building a fort on one of the islands, Garden Key. Fort Jefferson was designed to be a three-tiered fortress with 420 guns, but was never completed. It served as a military prison and four of the conspirators in the assassination of President Abraham Lincoln were incarcerated there. By 1888 the fort's military usefulness had declined and the expense of maintaining it in the face of the hostile climate and frequent hurricanes caused the military to hand it over to the Marine Hospital Service for use as a quarantine station.