Maritime history of Florida
Spain ceded Florida to the United States as part of the Adams–Onís Treaty of 1819, and Florida became a U.S. territory in 1821. Coastal trade with other markets continued to expand and towns like Jacksonville, Pensacola and Tampa became important ports. After becoming a U.S. territory, the federal government began building a series of lighthouses as aids to navigation along the coasts of Florida to mark dangerous headlands, shoals, bars and reefs.
Department of Florida
Department of Florida, was the military administrative department established by the Union Army. The Department of Florida was established on April 13, 1861 to defend and administer the few remaining Federal installations remaining in Florida. Following the secession of Florida in January 1861, Florida troops seized most Federal property in the state with the exceptions of Fort Zachary Taylor at Key West and Fort Pickens at Pensacola. The Union Navy would use the port of Key West to establish a blockade of the Atlantic and Eastern Gulf coasts of the Confederacy, with the South Atlantic Blockading Squadron and the East Gulf Blockading Squadron.