Gunrooms-Fort Jefferson-Dry Tortugas National Park - Key West FL
Posted by: Groundspeak Regular Member Don.Morfe
N 24° 37.674 W 082° 52.368
17R E 310428 N 2725038
The 8- and 10-inch columbiads were standard U.S. cannon for coast defense. They were cast-iron, muzzle-loading smoothbores. The 8-inch weighed 9,210 pounds and when elevated 4” threw a 65-pound ball about a mile.
Waymark Code: WM135RH
Location: Florida, United States
Date Posted: 09/22/2020
Published By:Groundspeak Premium Member tiki-4
Views: 4

Gunrooms Fort Jefferson— Dry Tortugas National Park —The 8- and 10-inch columbiads were standard U.S. cannon for coast defense. They were cast-iron, muzzle-loading smoothbores. The 8-inch weighed 9,210 pounds and when elevated 4” threw a 65-pound ball about a mile. From the top of the fort, the 10-inchers (15,400 pounds) could be elevated to 39” and throw a 128-pound shell over three miles.

The fort had no guns when Major L.G. Arnold and his 66 artillerymen arrived from Boston, January 19, 1861. As they worked on the first gun mount, a courier from an armed vessel came ashore and demanded surrender to the State of Florida. When Arnold met the messenger, he rushed to his gunport. "Tell your captain," he shouted to the messenger, "I will blow his ship out of the water if he’s not gone in ten minutes!"

The bluff worked. By the time war began in April, Arnold had mounted 68 cannon.

Technically, gunrooms are “casemates.” This fort has 303 of them. A thick wall in front and strong vaulting above protected guns and men from enemy fire. Open backs and overhead vents carried off heat and smoke.

Though designed to deliver the most concentrated firepower of its time, Fort Jackson never received more than 141 guns - a third of its full armament - because of structural failure.



LOCATION: Marker is in Key West, Florida, in Monroe County. The marker is located on the grounds of Fort Jefferson, Dry Tortugas National Park. Marker is in this post office area: Key West FL 33040, United States of America.
Marker Number: 1111

Date: 1/1/1990

County: Monroe

Marker Type: Roadside

Sponsored or placed by: National Park Service, U.S. Department of the Interior.

Website: [Web Link]

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