Defending US Commerce

Fort Jefferson stood at the gateway to nearby landmasses and important shipping routes despite its seemingly isolated location. To the south lay Cuba, to the east Key West, and to the north a critical deepwater harbor, the main reason the fort was built there, along with routes leading to major ports around the Gulf of Mexico and the Yucatán Peninsula. The site occupied a maritime crossroads later used more often by cruise ships and freighters than by military ships.