Delving into the history of Fort Jefferson at Dry Tortugas

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Walking through the lonely corridors of Fort Jefferson, with sweat dripping from every limb on a scorching hot day, I quickly realize why the prisoners who were held here in the Civil War era considered it hell.

Fort Jefferson may be located on a scenic tropical island in what is now Dry Tortugas National Park, but inside this fort, there’s no sense of the beautiful Gulf of Mexico waters that lie just beyond the 50-foot-high, 8-foot-thick walls.

The only windows to the outside are the small openings where cannons used to sit, ready for battle. More than 800 prisoners stayed here, including four convicted in the plot to assassinate Abraham Lincoln. One of them, Dr. Samuel Mudd, would end up playing a major role in solving the yellow fever epidemic while working as the fort’s doctor.

Generally, you don’t expect to find such a rich history on an isolated tropical island, but Fort Jefferson holds many surprises.

Seeing Fort Jefferson

Whether you fly or boat into Dry Tortugas National Park, you’ll spot Fort Jefferson on Garden Key from miles away.


You can see the big rows of cannon holes halfway up the fort, and you can see smaller cannon holes near the top and bottom. The top role of “holes” is actually fake – they’re just small indentations designed to look like cannon holes. It’s all about intimidation and fooling potential enemies!


These days, some of the cannon holes serve as balconies for NPS members who reside in the fort. Cool!


Why was Fort Jefferson built, anyway? Its initial purpose was to combat piracy and protect American shipping lanes in the Caribbean. The U.S. began talking about building such a fort in the 1820s, just five years after buying Florida from Spain. Construction began in 1846.

You may notice that the top section of bricks is darker than the rest. That’s because the fort was constructed mostly from Florida bricks, but once the Civil War began, Florida was part of the Confederacy and refused to supply bricks, so the Union forces that controlled the fort shipped in darker bricks all the way from Maine.


There’s a moat around Fort Jefferson. Moats are something you usually read about in ancient stories about castles, so it’s a trip back in time to see the moat.

Moats in fictional stories usually have a bunch of alligators in them. Well, this one does too! Kind of. There’s a single American crocodile at Dry Tortugas. It arrived here on its own many years ago, mostly likely from the Everglades area. It often hangs out in the moat, though it sometimes leaves to swim to other islands in the park. There are warning signs everywhere advising tourists to watch for the croc, but it has never had an encounter with a human.


Update: Less than a week after my visit, the croc was removed by officials and relocated to the Everglades over concerns about tourist safety.

Going inside Fort Jefferson

You can explore Fort Jefferson on your own, or take the daily one-hour tour. The tour is worth it for all the interesting tidbits of history the guide provides.

When you enter the fort, you’ll see a courtyard area in the middle with a few trees and old buildings and ruins. There are two main levels of the fort, as well as a roof, and you can access all of these areas via staircase.



On the tour, you’ll learn about the history of the fort, how it became a prison, how rainwater was collected, details about the barracks where soldiers used to live, and how the fort was eventually turned into a national park. You’ll learn about the fort’s recent history, such as the occasional boats of Cuban refugees that land here seeking sanctuary.


One of the coolest visual highlights is seeing the long corridors on the first floor. These long hallways with the arches make for great Instagram photos.



You can look out through the old cannon holes. It’s interesting that despite all the time and effort that went into constructing the fort, not a single shot was ever fired here.


Be sure to go to the roof for the most amazing park views. Just be careful – there are no fences or handrails so you could easily walk right off the edge if you’re not paying attention.



The cannons are enormous. Feel free to play around with them as much as you want.


I love the fact that a cactus was growing 45 feet in the air on the roof. Surrounded by so much water, yet still hot and dry.


You can see many of the nearby islands from up here and you get a great view of the snorkelers on the island. One guy told me that while he was up here, he saw a small shark (4 feet or so) swimming on the north side of the fort just outside the moat.

The fort officially closes at sunset, but a lot of people do stay up here until then to view the unobstructed sunsets in the Gulf of Mexico.

sunset dry tortugas

Samuel Mudd’s stay at Fort Jefferson

Dr. Samuel Mudd was one of several people implicated in the Lincoln assassination, and after avoiding the death penalty by only one vote, he was sentenced to hard labor at Fort Jefferson.

His cell was on the second level just above the fort entrance, and it’s open to visitors (though it was closed for repairs when I was there.) There was plenty of other Mudd memorabilia available. Like this drawing that he made of the fort.


Why is Mudd so notable? Well, in 1867 an outbreak of yellow fever began killing many inmates, as well as the fort’s doctor. Nobody knew how it was spread. Because of his background, Mudd agreed to take over as doctor.

He was instrumental in uncovering the realization that the disease was spread by mosquitoes, and he ending up saving a lot of people at the fort. For his work, he was pardoned and released by President Johnson in 1869.


For more info, check out the Smithsonian’s fascinating article “How Samuel Mudd Went From Lincoln Conspirator to Medical Savior.”

Getting to Fort Jefferson

To get to Fort Jefferson, arrive in Key West and take the Yankee Freedom ferry over to the island. Either stay for a 4-hour day tour, or bring a tent and camp overnight (reservations must be made far in advance.)

Even if you’re just here to soak in some rays and see some barracuda through your snorkel, take an hour to explore the fort and you’ll get a much better sense of appreciation for this place.

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