Fort Jefferson: Archaeological divers at Dry Tortugas National Park in Gulf survey submerged Civil War-era graves

Grad student Devon Fogarty at John Greer's grave (C. Sproul/NPS)

A submerged Gulf of Mexico island reportedly spotted from the air a few years ago contains a cemetery holding the grave of a laborer who died at Fort Jefferson, the Civil War-era fortress.

Dry Tortugas National Park recently announced the discovery of the cemetery and the remains of a small 19^th-century quarantine hospital. The latter was used to treat yellow fever patients at the fort between 1890 and 1900. The park is 70 miles west of Key West, Fla.

Laborer John Greer died in the first year of the Civil War. The isolated Fort Jefferson is mostly associated with that time, when it held Confederate prisoners and Lincoln assassination conspirators.

Water color depicts hospital and cemetery on Dry Tortugas island (NPS)

The park released photos and video of the fascinating August 2022 find near Garden Key, with a maritime diver checking out Greer’s grave not far from the surface.

Research shows the post cemetery contains dozens of graves of US military personnel, prisoners and civilians who were at Fort Jefferson or nearby islands. Greer died at the fort on Nov. 5, 1861. His cause of death is currently unknown.

His grave was marked with a well-preserved large slab of greywacke, the material used to construct the first floor of Fort Jefferson. The slab was carved into the shape of a headstone and inscribed with his name and date of death. Greer’s is the only currently identified grave on the sand.

Greer's grave stone is still legible (C. Sproul/NPS)

“This intriguing find highlights the potential for untold stories in Dry Tortugas National Park, both above and below the water,” Josh Marano, maritime archeologist for the south Florida national parks and project director for the survey, said in a statement. “Although much of the history of Fort Jefferson focuses on the fortification itself and some of its infamous prisoners, we are actively working to tell the stories of the enslaved people, women, children and civilian laborers.”

Marano told The New York Times he noticed a strange pattern in the water while he was flying over the Gulf of Mexico in 2016. He then pored over nautical charts. “There was dry land here at one point. There was a structure on that island at one point,” Marano told the newspaper. “When did it disappear?”

The archaeologist and students surveyed the island last summer and have since been conducting more research.

John Greer's name appears on 1861 roll at Fort Jefferson (NPS)

Park officials note a couple factors that may explain why this island is now below water.

“While the facilities identified in this survey were originally built on dry land, the dynamic conditions caused many of the islands to move over time. Climate change and major storm events have even caused some islands to settle and erode beneath the waves.”

Fort Jefferson was ringed by other islands used for various purposes, including quarantine sites for ill military members, prisoners and civilians.

As the population of Fort Jefferson swelled, the risk of deadly communicable diseases, particularly the mosquito-borne yellow fever, drastically increased. Major outbreaks of disease on the island killed dozens throughout the 1860s and 1870s.

Fort Jefferson is surrounded by submerged and above surface islands (NPS)

The National Park Service’s South Florida National Parks Cultural Resources Program will monitor the archaeological site, and officials remind visitors it is protected by federal law.

Park cultural resources staff, assisted by members of the NPS Submerged Resources Center, the Southeast Archeological Center and a University of Miami graduate student conducted the 2022 survey. The park is not divulging the exact location of the site.

Fort Jefferson is accessible only by boat or seaplane. Visitors are required to provide their own food, water and all other supplies while at the park.