Fort Jefferson (1)
|Fort Calendar||Fort Blogs||
Fort Jefferson (1) (1846-1874) - Construction of this Third System fort began in 1846 supervised by the U.S. Army Corps of Engineers and continued for 30 years and was never completed. Named after President Thomas Jefferson. Located 70 miles west of Key West on Garden Key, Dry Tortugas Islands, Monroe County, Florida. Abandoned in 1874.
Fort Jefferson (1) History
Established to protect a critical point and as a base of operations in the Gulf of Mexico. The fort provided a safe harbor from enemies and weather.
Designed as the largest Third System brick and masonry fort in the U.S. Fort Jefferson was to be a three-tiered six-sided 420 heavy gun fort, with two sides measuring 325 feet, four sides measuring 477 feet and bastions at each corner. Some 16 millon bricks were used in its actual construction. Prior to the U.S. Civil War the bricks came from Pensacola and were yellowish in color, during and after the war the bricks came from Maine and were red in color. The line of construction where the bricks changed can be see at the very top of the fort Walls. The guns were to be mounted inside the walls in a string of 303 open vaulted casemates, facing toward the sea through large Totten embrasures, and along the top barbette tier. The third tier of casemates was never built.
The fort depended upon rain water as the only source of fresh water on the island and an elaborate system of cisterns was built into the foundations of the fort to catch and filter the rainwater. The cistern system failed after cracks developed in the cisterns because the foundations of the fort settled unevenly. The fort suffers from a lack of fresh water to this day.
Soldiers and officers quarters, gunpowder magazines, storehouses, and other buildings were located on the interior parade. A three story, 1000 man barracks dominated one side of the parade while a set of officers's quarters was built on the opposite side. A main magazine and a secondary magazine were located adjacent to the northeast and southwest casemates. A hotshot furnace was located behind the main magazine. The Army employed a variety of civilian contractors, paid laborers, military convicts and slaves to construct the fort.
This fort, like all the other Third System Forts was made obsolete by the adoption of large caliber rifled cannon that could penetrate the brick and masonry walls. The destruction of Fort Pulaski by Union batteries in Apr 1862 signaled the demise of the Third System Forts.
During the U.S. Civil War the number of Union military convicts increased so significantly that slaves were no longer necessary. The peak military population of Fort Jefferson was 1,729 and the total population almost 2000 with military dependents and civilians.
Fort Jefferson was abandoned in 1874.
- 1908 Wildlife refuge
- 1935 National Monument
- 1992 National Park
The park is staffed with about a dozen park rangers who live year round in accommodations built into the casemates of the fort.
Access to the island is provided by commercial boats and seaplanes based in Key West.
Location: 70 miles west of Key West on Garden Key, Dry Tortugas Islands, Florida.
Maps & Images
Lat: 24.628611 Long: -82.873333
- Roberts, Robert B., Encyclopedia of Historic Forts: The Military, Pioneer, and Trading Posts of the United States, Macmillan, New York, 1988, 10th printing, ISBN 0-02-926880-X, page 178-179
- Robinson, Willard B., American Forts: Architectural Form and Function, University of Illinois Press, Urbana, 1977, ISBN 0-252-00589-9, page 115-117
- Lewis, Emanuel Raymond, Seacoast Fortifications of the United States: An Introductory History, Naval Institute Press, Annapolis MD, 7th printing, 1993, ISBN 1-55750-502-0, page 43, 54,
- Weaver, John R. II, A Legacy in Brick and Stone: America Coastal Defense Forts of the Third System, Redoubt Press, McLean, 2001, First Printing, ISBN 1-57510-069-X, page 155-158
- National Park Service
- Park Vision
- Wikipedia - Dry Tortugas National Park
- Park Vision - Fort Jefferson
- Google Books
Visited: 29 Dec 2009
Fort Jefferson (1) Picture Gallery
Click on the picture to see a larger version. Contribute additional pictures - the more the better!