On October 26, 1992, Fort Jefferson National Monument was redesignated as Dry Tortugas National Park.
The park's centerpiece is Fort Jefferson, a massive brick fortress approximately 70 miles west of Key West.
One of its most famous prisoners was the doctor who treated President Abraham Lincoln's assassin.
Dr. Samuel Mudd was imprisoned at Fort Jefferson after treating John Wilkes Booth's broken leg following Lincoln's assassination in 1865.
In 1867, yellow fever swept through the remote prison. Mudd helped the prison's medical staff treat the sick. His sentence was commuted in 1869, and he was released.
The fort itself was an engineering nightmare. Construction began in 1846 and continued for approximately 30 years, but the structure was never completed. Sections began sinking into the unstable ground, forcing engineers to abandon part of the planned upper level.
At its peak, nearly 2,000 people lived inside the isolated fortress, including soldiers, prisoners, laborers and their families. Early construction relied heavily on enslaved laborers from Key West.