Fort Jefferson Key West – 70 miles to History

It is hard to believe that our ancestors in the 1800s could build a fort on an island 70 miles west of Key West. The island had no fresh water, very little cover from the heat and no inhabitants.
Not only did they build a fort off Key West, but they built the largest masonry structure in the Western Hemisphere.
Key West to Dry Tortugas Distance is Historically Significant
During the pre-Civil War planning of Fort Jefferson, the distance to the Dry Tortugas to Key West was significant for the purposes of protecting the Gulf of Mexico from foreign countries.
The United States had just been through two wars that proved the value of keeping Gulf Coast cities safe from foreign powers like Spain, Great Britain and France. The Northwest Passage, near Key West could be fortified by building a fort near Key West.
The short distance between Key West and the Dry Tortugas meant supplies could easily be transported to Fort Jefferson.
Fort Jefferson Key West Significance
Key West and Fort Jefferson have been intrinsically linked since the early 1800s. Even before the 1850s when Fort Jefferson was started. The Dry Tortugas, the islands that include Fort Jefferson, were fishing grounds for Key West fishermen.
Turtles (tortugas in Spanish) were the main harvest from the Tortuga islands. The turtle meat was used as a food source for many years until over fishing lead to a ban on harvesting most sea turtles. The area became known as turtle island Florida.
Today, Fort Jefferson – Key West are linked by the popularity of trips to the Dry Tortugas to see the Fort, now a huge tourist attraction.
How Long Did it Take to Build Fort Jefferson in the Dry Tortugas?
It took over 16 million bricks shipped in from Pensacola and over thirty years, but they built Fort Jefferson in the Dry Tortugas as a monument to man’s ability to overcome even the worst scenarios. Today the Fort near Key West is one of Florida’s most sought-after historical sites.
The Fort was authorized by both the Lincoln and Johnson administrations prior to the Civil War.
Named after President Thomas Jefferson, the Fort was started in 1846 with continuing construction until the Civil War. The fort had over 500 guns pointing all around the 15 acres it was situated on.
When the Civil War started, 160 soldiers were sent there to protect against the Fort falling into Confederate hands. At the same time, the Army thought this impenetrable fort in the middle of the Gulf would make a perfect place for prisoners of the Civil War.
Fort Jefferson’s Most Famous Resident
When President Lincoln was assassinated in 1865, Fort Jefferson got its most famous prisoner. Dr. Samuel Mudd was convicted of conspiracy to assassinate Lincoln and sentenced to life in prison at Fort Jefferson in the Dry Tortugas.
During this period, an outbreak of yellow fever killed many guards and prisoners. However, Dr. Mudd saved hundreds of lives by working tirelessly to fight the epidemic.
Mudd was subsequently pardoned and he went home to Maryland where he died in 1883 in Waldorf, Maryland.
Fort Jefferson Key West
Today, Fort Jefferson Key West is a national park named Fort Jefferson in the Dry Tortugas National Park. Tens of thousands of people visit the park annually as one of Florida’s top historical sites.
Most come from Key West, but some come in their personal boats and dock near the park.
From Key West, there are day trips from Key West Bite Marina daily. Boats take 2.25 hours. You spend the day and return by boat.
Our family’s favorite way to get to Fort Jefferson is taking a seaplane over to the Fort. We then tour Fort Jefferson and do some snorkeling in the waters surrounding the park.
As a side note, we saw the largest tarpon we have ever seen on a snorkeling trip at Fort Jefferson. Some old pilings there attract many varieties of fish and this tarpon weighed well over 200 pounds. He was hanging around looking for a meal.
Touring Fort Jefferson Key West

Your visit to the park will amaze you. You will wind through spiral brick stairways to get to the old bastions where cannons guarded the pass to New Orleans and other Gulf ports. You can do a self-guided tour or join one of the almost hourly tours by the Fort’s staff.
You will see the brick quarters of the soldiers and their lifestyle in what must have been a very secluded life. It should be noted that even in the 1800’s they knew how to distill fresh water from seawater. It was never enough and ships had to bring more fresh water regularly.
They produced about 7000 gallons a day which was not near enough but kept supplies going until rainwater filled their cisterns and the occasional water ship would come into port.
In the parade grounds that cover over 13 acres, there are remnants of their gardens where you can imagine the daily training. You can almost hear the bugle’s morning reveille mustering the soldiers!
Trips To Fort Jefferson From Key West
You can stop by any booth along Duval Street selling tickets and tours. They can assist you in booking a Fort Jefferson day trip in Florida.
Most people go by seaplane or charter boat. However, our favorite trip to Fort Jefferson was on a catamaran out of the marina. Take this trip for a day of fun, snorkeling and sightseeing — and most of all great memories!
Reservations are important. They should be made well in advance to make certain you will be able to join the tour. Both seaplane trips and boat trips sell out regularly.
When visiting the Florida Keys and Key West, you have many options for attractions, but Key West’s Fort Jefferson is one of Florida’s most popular historical sites you will never forget.
We highly recommend Fort Jefferson for all ages. The kids love it as much as adults. The history, beauty and unspoiled tranquility make it one of your bucket list attractions. Fort Jefferson is one of our top historical sites to visit in Florida.
Now you know what fort is in the Dry Tortugas, Fort Jefferson Key West!
Frequently Asked Questions About Fort Jefferson Key West
What is Fort Jefferson famous for?
Fort Jefferson is famous for being one of the largest brick masonry structures in the Western Hemisphere—and for its fascinating, somewhat wild history. It’s most famously known as the prison where Dr. Samuel Mudd—the doctor who treated John Wilkes Booth after Lincoln’s assassination—was held.
Is the Dry Tortugas and Fort Jefferson the same thing?
They’re related, but not exactly the same thing! Here’s the easy way to think about it: Dry Tortugas is the name of the entire island chain and national park — a cluster of seven small islands about 70 miles west of Key West. It’s famous for its clear waters, coral reefs, marine life, and remote, wild beauty. Fort Jefferson is one specific structure located on Garden Key, which is the largest island in the Dry Tortugas. It’s a giant, historic brick fort that pretty much covers the whole island.
How long does it take to get to Fort Jefferson from Key West?
Getting to Fort Jefferson in Dry Tortugas National Park from Key West is an adventure in itself! You have two main options: ferry or seaplane. The ferry is about 2 hours and 15 minutes each way. The seaplne is about 45 minutes each way. A favorite way is by catamaran from Key West, which takes about 2.5 hours each way, but allows a lot of time for exploring and snorkeling. The total trip is 10 hours.
Why was Fort Jefferson abandoned?
Fort Jefferson was abandoned mainly because it just became too expensive, impractical, and unnecessary to keep it running. Building a giant fort on a remote island with limited fresh water, shifting sands, and constant hurricanes turned out to be a nightmare. The fort was never even finished after 30 years of work. It was officially abandoned as a military post in 1874, though it was used off and on after that for small operations like a quarantine station and lighthouse maintenance. Today, it stands as a ghost of that old era—an epic, crumbling fortress surrounded by some of the clearest water in the Keys.
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