Fort Jefferson on Garden Key in Dry Tortugas National Park

VISITING FOR JEFFERSON

Fort Jefferson is the dominate feature of Garden Key, taking up about 85% of the small island. Visitors can explore the fort on their own from sunrise to sunset utilizing a self-guided tour route that starts from the Dry Tortugas Visitor Center inside the fort. A printed brochure is available (if you can find one), or you can read the information panels that are placed along the way. Look for the signs featuring a marching soldier and walk in the direction the soldier is facing.

Follow the signs for a self-guided tour of Fort Jefferson

Another way to learn about the fort is to attend a guided tour at 11 AM each morning that is conducted by the staff of the Yankee Freedom Ferry. During the tourist season there may be an additional tour at 1 PM that is given by a park Ranger if staffing allows. The early tour is the most popular, as it is given just after the ferry arrives. If a tour is important to you, this is the one to get on, for there may not be one later in the day.

Fort Jefferson guided tour

Whether you do your own tour or attend one of the guided tours, plan to spend one hour inside the fort. Keep in mind that the fort is huge and that the guided tours do not cover everything, so if you have a big interest in military history, you may want to spend another hour walking around on your own. If you came over on the ferry for a day trip, you’ll need to weigh your time at the fort against time for other activities such as swimming and snorkeling, for you only get about four hours on the island.

Regardless of your interest in history, make your way to the top level of Fort Jefferson for the most spectacular views of the island. The fort is six-sided, and you can walk around on four of the sides. This gives you views in nearly all directions.

Great views from all around the top level of Fort Jefferson

You can also get good views and photos of the fort from the moat wall. However, due to a breach in the wall, it is no longer possible to walk around the entire fort.

A walk along the moat wall is a popular activity at Garden Key

Fort Jefferson as seen from the moat wall

Breach in the moat wall at Fort Jefferson

FORT HISTORY

Construction on Fort Jefferson began in 1846 as part of the United States’ effort to strengthen coastal defenses as a result of how easily the British were able to blockade and even invade American cities during the War of 1812. This included successfully burning Washington, D.C., to the ground. Today you might wonder what’s so bad about that, but back in the early 1800s it started a national panic. This age of fort construction was termed the “Third System,” and from 1816 though 1867, forty-two forts were built. Many of the forts that are still standing today are part of the National Park system.

In a time before airplanes, any foreign enemy that wished to invade a country on another continent had to do so by ship, and ships could not attack or launch an amphibious assault from just anywhere along the coast. Water deep enough to accommodate a large ship was needed, and a ship had to get close enough to shore so its cannon fire could pound the area and its soldiers could land in their small boats. Of course, most such places are occupied by major cities, for deep water was coveted in peaceful times for its impact on commerce. Thus, in the United States, most of the new forts were built near cities, with one notable exception being Fort Jefferson at Dry Tortugas.

So why build a fort out in the middle of the Gulf of Mexico? Wouldn’t it be easy enough for ships to just sail right around it? After all, the cannon at the time only had a range of a few miles? As it turns out, the most efficient way for ships from South America or farther west in the Gulf of Mexico to travel to the east coast of the United States was to sail between Florida and Cuba, and the only channel deep enough for the largest ships ran right in front of Garden Key. In addition, there is a deep-water harbor just a mile north of Garden Key that was a perfect base for United States warships. Even if enemy ships got around Fort Jefferson, they would still have to face an American fleet stationed in the Gulf.

Fort Jefferson, like all forts of its time, was a masonry fort built of stone, or in this case, brick. Brick had no problem stopping a typical cannonball, for these did not travel with much velocity, nor were they very accurate, so the chance of blasting a hole in the fort wall by hitting the same spot over and over was slim. However, rifled artillery shells were developed during the Civil War. Instead of round balls, rifled shells looked like large bullets and spun like a football when fired. This allowed them to travel faster and with more accuracy, and they could blast through a masonry wall in no time. Case in point: Fort Pulaski.

Rifled shell and cannon ball exhibit at the Dry Tortugas Visitor Center

Like the Titanic was deemed “unsinkable,” Fort Pulaski near Savannah, Georgia, was supposedly impenetrable. Fittingly, just as it was ironic that the Titanic would sink on its first voyage, so was it that the Union Army was able to blast a hole through Fort Pulaski’s walls by using the new rifled artillery shells the first time it saw battle. But this was not just any hole. Engineers who built the forts during the time of peace all ended up on opposite sides during the Civil War, which meant that no matter what fort you occupied, your enemy probably had an engineer who knew its weaknesses.

The Union knew where to blow a hole so that when subsequent artillery shells entered that hole, they would bounce across the parade ground towards the gunpowder magazine on the opposite side. The commander of Fort Pulaski, Charles H. Olmstead, realized the entire fort could blow up at any minute, and he quickly surrendered. Thus, the surrender of Fort Pulaski marked the day when all coastal forts effectively became obsolete. As a result, after the Civil War, continued construction on forts that had not yet been completed, like Fort Jefferson, ceased.

In some cases the interiors of the masonry forts were fitted with concrete bunkers and batteries (Fort Sumter, for example) that could withstand rifled shells, while others were converted into command centers, offices, and training grounds. None of the original structure served any purpose as far as defense was concerned. Fort Jefferson was used as a military prison, though this practice actually started during the Civil War for the simple fact that there wasn’t much fighting going on 70 miles west of Florida to begin with. No shots were ever fired from or upon Fort Jefferson.

The U. S. Army occupied Fort Jefferson until 1898. After that it was under the Navy’s control and used as a fueling station until 1916. During this time, in 1908, the Dry Tortugas area became a wildlife refuge to protect the island’s sooty tern rookeries from being ransacked by egg collectors. In 1935, with Fort Jefferson now abandoned and rapidly deteriorating, Congress created the Fort Jefferson National Monument to help preserve the fort. However, it was not until 1992 that the park’s land holdings were increased, and the Monument was reclassified into Dry Tortugas National Park.

When you stand outside the fort today you may notice that the second level has huge, window-like holes of various sizes in the exterior wall. Most people assume these are a result of bricks falling out over the years or perhaps areas damaged when the fort took enemy fire—neither is the case. Holes in the fort walls are designed so that cannon can fire out of them, and such holes, known as gunports, should look like the smaller holes on the first and third levels of the fort. The holes on the second level are not a result of damage, but are simply gunports that were never finished.

Second level gunports were never completed

Even though construction began in 1846, by the time the Civil War came around Fort Jefferson was nowhere near completed (the Union Army controlled the fort during the war). It was vital to place cannon on the top level of the fort, which was not yet ready, and thus it was ordered to construct the second level only to the extent that it could support the weight of the structure above it. Once done, efforts on the second level ceased and all resources were put into completing and arming the top level. The unfinished second level was eventually used as housing for the enlisted men and as a military prison during and after the Civil War. The gunports were never finished and remained as large holes.

The second level holes now make great picture frames

SELF-GUIDE TOUR OF FORT JEFFERSON

Begin your tour of Fort Jefferson by crossing the moat bridge and entering onto the fort grounds through the sally port, the term for the main entrance of a fort.

Sally port of Fort Jefferson at Dry Tortugas National Park

Once inside you will see a series of rooms framed by brick archways. These rooms are called casemates, and each was designed to house an artillery piece. You can get to the bottom floor casemates without using any stairs. There are a few exhibits here and there, but most are empty. There are 303 first and second floor casemates.

Casemates of Fort Jefferson

Inside the casemates

To get to the second and third levels of Fort Jefferson you must go to one of the corners where the bastions are located. Inside is a spiral staircase that you can take to the top. The bastions are the only way to get to the upper levels.

Corner bastion at Fort Jefferson

Bastions are structures that protrude out from the corners of the fort that allow men stationed inside to have a clear view of the fort walls. In addition to armed soldiers, short range artillery pieces were mounted inside, and any invader who approached the walls would be trapped in a crossfire between two bastions.

Line of sight from one bastion to the next along one side of the fort’s walls

Once on the top level, you can walk around four sides of Fort Jefferson on a gravel path. Two of the sides are off limits, as they contain National Park Service equipment, housing, and offices.

Visitors can walk around four of six sides on the top level of Fort Jefferson

On the top level is where you will find various cannon exhibits. The largest of all cannon are the Rodman guns, which could fire a projectile up to three miles. The Rodman guns are original to the fort. A contractor was hired to remove all artillery after the fort was decommissioned, but the Rodman guns were so heavy that the contractor left them. Most are sitting atop a metal stand, but one is actually displayed on a carriage that is a reproduction of the original design. All other cannon, which include Parrott guns, are actual artillery pieces manufactured in the 1800s, but they are not original to the fort; they were moved here for exhibition purposes.

Original Rodman gun with reproduction carriage

200-pounder Parrott gun

There is also a lighthouse on the top level of the fort. The original lighthouse was completed in 1826 and was a 65-foot tower built on the ground. However, the light did not reach far enough out to sea because it was too short. Eventually a much larger lighthouse was built on Loggerhead Key in 1858. The Garden Key Lighthouse was severely damaged by a hurricane in 1873. Repairs were initially made, but it was then decided to tear it down and build a new one on the top of the fort walls. It was installed and ready for service in 1876 and continued in service until 1921. The lighthouse is not open to the public. It still operates today as a navigational guide, but with GPS and other modern equipment, it’s really more of tourist attraction than a necessity for boaters.

Garden Key Lighthouse

If you look down onto the parade grounds you will see a large, semi-circular structure that was supposed to be the main gunpowder house, but like many things in the fort, it was never completed. When finished it would have been completely encased in concrete. Mini-powder houses, known as traverse magazines, are located on the top level of the fort. These were used to supply the adjacent artillery with gunpowder. The traverse magazines are the large, trapezoid-shaped structures on the top level that are partially covered with sod.

Main powder house that was never completed

Another view of the powder house

Inside the incomplete powder house

Once you have covered all of the top level of Fort Jefferson you can take the bastion stairs down to the second level and explore this floor. Like the first floor casemates, most are empty, but you will find a few exhibits.

View of the interior of Fort Jefferson from the top of the fort

Casemates form an unending series of empty rooms

As mentioned earlier, the second level was used as a military prison, and it is here where you will find the jail cell of Dr. Samuel Mudd, the most famous of all prisoners held at Fort Jefferson. Mudd is the doctor who set John Wilkes Booth’s broken ankle after he assassinated Abraham Lincoln and escaped from Ford’s Theater. Mudd was convicted of being a co-conspirator, though his guilt has been questioned by many. He obviously knew Booth, but he may have just been a doctor who was in the wrong place at the wrong time. He was eventually pardoned by President Andrew Johnson for his bravery during a yellow fever epidemic at the fort.

Dr. Mudd’s cell

Memorial plaque at Dr. Mudd’s cell

Though the empty casemates on the second floor served as housing for both prisoners and soldiers, actual barracks were built on the grounds of Fort Jefferson beginning in 1863. Like the fort, they were never fully completed. While men lived in the finished portions, most preferred the empty casemates because they were more spacious and cooler due to increased airflow.

There were three buildings constructed: Officers’ Quarters, Enlisted Men’s Barracks, and Engineering Officers’ Quarters. The only building remaining today is the Engineering Officers’ Quarters, which was converted into housing for the National Park Service staff back in 1941. The Officers’ and Enlisted Men’s barracks became dilapidated and were torn down. The Enlisted Men’s Barracks was a huge building, three stories tall like the fort itself.

Ruins of the Officers’ Quarters

Foundation of the Enlisted Men’s Barracks

Engineering Officers’ Quarters

One other interesting structure on the grounds of the fort is a shot furnace. Cannon balls were placed inside and heated so that when they were shot towards wooden ships, they might cause a fire. Shot furnaces were standard equipment in all forts of the time. Steel ships and rifled artillery rounds made them obsolete in the years following the Civil War.

Shot Furnace

Fort Jefferson is in need of constant repair. Over sixteen million bricks were used to build the fort, and if you walk around it today, you will see sections of brick that have crumbled and fallen into the moat, though in the photo below the two large areas of missing brick were created by the National Park Service in preparation for new bricks. The light-shaded bricks on either side of the two missing sections are new bricks that were recently installed. There are at least five different shades of brick in the photo. This is a result of not being able to use the same source over the years. During the Civil War, the Union occupied the fort and could no longer get bricks from Florida, the original source, and had to ship them in from northern factories.

Fort Jefferson endures constant decay

One of the most interesting exhibits at Fort Jefferson is two boats used by Cubans to escape to the United States. Per legislation passed while Bill Clinton was President, any Cuban who could land on American soil got to stay in the country and pursue citizenship (Barack Obama ended the policy in 2017). The keys of Dry Tortugas and Key West are the closet to Cuba, but it is much easier to land at the remote islands of Dry Tortugas verses the heavily populated Key West. The boats on display are from a 2007 landing by 33 Cubans on Loggerhead Key. These two boats are located in the lower level casemates.

One of two makeshift boats known as a “chug” that carried 33 Cubans to Loggerhead Key in 2007

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