Tag: lighthouse

situated on Garden Key, Fort Jefferson is the largest masonry structure in the Western hemisphere and served as a military prison and outpost during the 19th century. located 70 miles west of Key West, it sits at the tail end of the archipelago and, really, ought not to support human life. the collection of islands originally got their name from the sea turtles that nested there; in short order map-makers added the “dry” designation to warn sailors of the lack of potable water. upon scouting the keys for possible military installations, Commodore David Porter reported that the Dry Tortugas consisted of sand islands barely above the surface of the ocean with scarcely enough land to permit construction of a fort, much less support one without sinking below the waves.

the moat from the atop the walls of the Fort

Porter’s observations not withstanding, the government determined the islands useful to house, at the very least, a lighthouse. three years after Porter’s initial observations, a successor stressed the strategic importance of the islands in the Gulf shipping channel, prompting movement on a permanent, fortified outpost to defend U.S. interests.

harbor light atop the Fort wall

work on the structure began in 1846 and never finished, though construction (by slaves and prisoners) continued for 30 years. the original lighthouse stood within the fort walls but, after it suffering damage during a hurricane, was relocated to Loggerhead Key some 2.5 miles distant. the design originally called for a three-tiered, six sided brick structure; the sides met at corner bastions, which allowed some of the 410 guns to fire along the walls at ships crazy enough to come within range of the cannons. most of the armory and artillery improvements went unused. my favorite one, which I’m almost sad never got used, was a building designed to heat up cannon balls so that, when fired at enemy ships, the shot would start the wood on fire, burning and sinking the ship simultaneously. as construction progressed, however, concerns arose that further weight would cause the structure to sink (further) and result in further damage to the cisterns and undermine stability of the fort.

cells were left open to the elements, to prevent added weight

at its peak, some 2,000 people lived at Fort Jefferson, including military personnel and (occasionally) their families, prisoners, and (prior to the Civil War) slaves. it served as a harbor for war ships defending Gulf ports, such as Pensacola, New Orleans, and Mobile, general deterrent for anyone considering an attack against U.S. merchant ships, and evocative symbol of America’s intentions towards any potential aggressors (we’re lookin’ at you, Mexico!).

 it remained under Union control throughout the Civil War, which resulted in some tensions with Key West, which, naturally, fell under Confederate control. Union ships used Fort Jefferson as a port in the blockade of Southern ports and it became a military prison, primarily for Union deserters, but also for special civilian prisoners, including Dr. Samuel Mudd. following his assistance during a yellow fever outbreak in 1867, President Andrew Jackson pardoned and released Mudd and, in 1874, the Fort ceased to function as a military prison.

balls placed at the far end heated up as they came down the chute

while Fort Jefferson was more or less abandoned by the Army in 1874, it did prove useful in other ways over the next half-century. the Navy used it as a coal refueling station for warships (we got to snorkel around the refueling dock pylons — lots of very cool fish); it served as a quarantine station for a time; the USS Maine sailed for Havana from Fort Jefferson, and other warships followed during the Spanish-American war; a wireless station operated from it around the turn of the 20th century; it briefly served as a seaplane base during the First World War.