Fort Jefferson: An Un-attacked Stronghold

It was in February 1861, just two months before the Civil War began, when seceding southern states began to seize control of federal forts after President James Buchanan denied them. 

Fort Jefferson, despite being located in the Florida Keys, was one of few Federal bastions located in the South that would remain under Union control throughout the entirety of the Civil War. It is a sprawling fortress that covers 16 acres and is the largest brick masonry structure in the United States, consisting of more than 16 million bricks. 

The fort’s powder magazine

Following the War of 1812, it was decided that coastal defenses must be established, and scouting for ideal locations began. Additionally, it was hoped that the defenses further south would help to suppress piracy in the Caribbean.

Commodore David Porter

US Navy Commodore David Porter began looking for a location to build the base shortly after Spain sold Florida to the United States in 1819. He inspected the Dry Tortugas (located in the southern Florida Keys), but dismissed the location due to a lack of fresh water and sturdy ground. Others preferred the Dry Tortugas and a lighthouse known as Garden Key Light was constructed there in 1825-26. 

A second survey of the Dry Tortugas, conducted in 1829, found that enemy occupation of the area would threaten shipping in the Gulf of Mexico as well as the Mississippi River. However the land would not be secured for military use until 1844, with support and recommendations from Captain John G. Barnard and Robert E. Lee, a captain at the time.

Construction began one year later under the watchful eye of then 2nd Lt. Horatio Wright. The fort’s design consisted of a three-tiered, six-sided building in which the walls would meet at corner bastions allowing for better defense of the facility.  Simply put the fort was designed to be a large gun platform, with enough large guns and men to destroy any enemy ships that may venture into the treacherous water.  

As mentioned above, Fort Jefferson remained firmly in Union hands throughout the Civil War. And while you may think this the result of its impressive arsenal, the reality is much less exciting: the Confederates never launched an attack against it. 

View of interior casemates and some of the Parade grounds

When the Civil War began, 62 men of the 2nd US Artillery Regiment under the command of Major Lewis Golding Arnold were sent to protect Fort Jefferson. The fort’s total population, including women and children, was roughly 170 people. The fort’s population more than doubled by July of that year as more soldiers arrived from the 6th New York Zouaves under the command of Colonel Bill Wilson.

The prisoner soldiers began to arrive in September 1861. These were court-martialed men sentenced to confinement and hard labor far away from the theater of war. At its peak in 1864, Fort Jefferson housed nearly 900 prisoners with just over 600 soldiers to guard them. A total of eight prisoners escaped Fort Jefferson, but their fates are unknown. Those sentenced found it to be a fate worse than death. The harsh working conditions in the blazing heat of the tropical island, compiled lack of food and fresh water, earned the fortress the nickname Devil’s Island. 

Dr. Samuel Mudd, circa 1866-1867.

Perhaps the most famous prisoners to be held at Fort Jefferson are four men who aided John Wilks Booth after he assassinated President Abraham Lincoln: Dr. Samuel Mudd, Michael O’Laughlen, Edmund Spangler and Samuel Arnold. A total of seven men and one woman were tried and found guilty in connection to the crime; four were sent to the fort and four were hanged. 

Dr. Mudd, who patched up Booth’s foot and gave him a place to stay after the assassination, was found guilty of aiding and abetting a criminal becuase he failed to report Booth’s location. He was not believed to be directly linked to the crime, however, and was allowed to work in Fort Jefferson’s hospital. 

This special treatment changed after Dr. Mudd was found attempting to escape the island on a steam transport. He was returned to the fort and thrown into a ground-level gunroom known as “the dungeon” with the others charged in Abraham’s assassination. The prisoners worked 12 hours each day wearing heavy leg shackles. 

Dr. Mudd was permitted to exchange letters with his wife, and his gruesome description of the dungeon prompted his wife to contact President Andrew Johnson for help. The War Department ordered the men be moved to better living quarters and their shackles removed. By 1866, they were returned to Fort Jefferson’s general prison population. However, Mudd was no longer permitted to work in the fort’s hospital, rather he would be assigned to the fort’s carpentry shop. 

In 1867 the fort faced a different enemy, Yellow Fever; the outbreak took the life of the fort’s only doctor. Seizing the opportunity to return to his profession once again, Dr. Mudd volunteered to work directly with yellow fever patients. Overtime, his work during the crisis led to a presidential pardon from Andrew Johnson in 1869.

Aerial photo of Fort Jefferson, as part of the Dry Tortugas National Park

Believe it or not, construction on Fort Jefferson continued well past the end of the Civil War. A large seawall finished in 1872 brought the total number of large caliber guns to 243, but none were ever fired. 

By 1874, with construction still progressing, only a handful of soldiers were stationed at Fort Jefferson. It’s important to note that the fort was never fully constructed, and despite its immensity is still considered to be unfinished.

By 1894, the fort was virtually abandoned save its occasional use as a quarantine station by the Marine Hospital Service. It wasn’t long until the fort fell into disarray and some of the problems first voiced by Porter became apparent. 

Fort Jefferson remained unoccupied until 1898, when the Spanish-American war broke out and it was necessary to once again staff the coastal bastion. The site was established as a Federal Bird Reservation in 1908 but by 1934 was nothing more than a crumbling ruin. In 1935, President Franklin D. Roosevelt designated the area as Fort Jefferson National Monument and the WPA began work to renovate and preserve the area. Fort Jefferson was added to the National Register of Historic Places in 1970 and became a National Park in 1992. 

2 Responses to Fort Jefferson: An Un-attacked Stronghold

  1. Thanks for this concise introduction to the Dry Tortugas. Sometimes connections are to be found in the most obscure places… and nowhere is more obscure than Fort Jefferson.
    In one of the ironies of the early Civil War, best described as stalemate at Pensacola, intense training was underway, conducted by the Rebels under Braxton Bragg in occupation of Forts Barrancas and McRee, the Advanced Redoubt, and the recently expanded Navy Yard. This training included sentry duty and patrols, artillery operation, cavalry utilization, and infantry drill. While less than two miles away Federal forces stretching away perhaps three miles east of Union- occupied Fort Pickens conducted virtually no training at all. And the man responsible for this wasted opportunity was Colonel Harvey Brown, 65 years old and 1818 graduate of West Point. Colonel Brown had replaced Major Israel Vogdes, who had replaced Hero of Fort Pickens, Lieutenant Adam Slemmer (Slemmer and his 80 defenders had been shipped north to New York to recover from scurvy and exhaustion.) And in exchange, New York sent south Colonel Billy Wilson and his toughs from the Bowery. During the weeks prior to arrival at Fort Pickens, New York newspapers printed grand pronouncements by men of Wilson’s 6th New York (Zouaves), stating how “they would be home soon, after beating the Southerners into submission,” and “No one was a match for a street-smart New Yorker.” Copies of the boasting newspaper reports reached Florida ahead of Billy Wilson, angering Southerners (who vowed revenge) and the man who would be Wilson’s boss, Colonel Harvey Brown. In addition, it is obvious from reading period reports that Harvey Brown 1) was not a fan of the Zouave movement; and 2) had no time for non-Regular “soldiers.” When the 6th New York arrived on the white sand of Santa Rosa Island 24 June 1861 they were ordered away east, at least one mile away; and Colonel Harvey Brown and his Regular Army (mostly artillerists) stayed inside Fort Pickens and manned a handful of artillery outposts.
    Meanwhile, Harvey Brown reported to Washington that he was undermanned. In order to acquire more “trained soldiers,” Colonel Brown removed men from Billy Wilson, dozens at a time, and sent them south to Fort Jefferson. In exchange, Regular artillerists from Fort Jefferson were sent to Colonel Brown, one for one. Even Major Lewis Arnold, the commander of Fort Jefferson, was eventually removed to Harvey Brown’s security force inside Fort Pickens. And within a few weeks, the 6th New York Zouaves on Santa Rosa Island, charged with guarding the eastern approach to Fort Pickens, were reduced to half of their arrival number.
    What could go wrong?

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