United States territorial acquisitions
West Florida was declared to be a U.S. possession in 1810 by President James Madison after the territory had declared its independence from Spain. Madison ordered the U.S. Army to take control. Six weeks later, the army entered and occupied the capital, St. Francisville, putting an end to the republic after 74 days of independence. Spain did not relinquish its claim to sovereignty (see West Florida Controversy) until ratification of the Adams–Onís Treaty. General Andrew Jackson personally accepted the delivery of West Florida from its Spanish governor on July 17, 1821.
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.