During the Civil War the fort was a military prison for captured deserters. It also held 4 men convicted of complicity in President Abraham Lincoln's assassination in 1865. The Army abandoned Fort Jefferson in 1874, and in 1908 the area became a wildlife refuge to protect the sooty tern rookery from egg collectors. Dry Tortugas NAtional Park was made to protect the historical and natural features. There are many things that you may enjoy at the Park such as beach combing, birdying, camping, diving, fishing, hiking photography, ranger led activities, snorkeling, swimming, and wildlife watching.
Many people visit the park to because the underwater photography is amazing there.
Humans mostly illegally hunt for gourmet meat, leather, and cosmetic oils, sea turtles numbers have gone down greatly worldwide, but green, loggerhead, and hawksbill species are still seen in the Dry Tortugas. The Park is opened all year around but the best times to visit is November through April. During the summer the Key are hot and humid and the insect might swarm and bite.