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
On March 15, 1862, the Department of Florida was merged into the Department of the South.
At the end of the Civil War, a new Department of Florida, subordinate to the Military Division of the Gulf, (1865–66) was established by the United States Army on June 27, 1865. It remained until 1866 when it was merged into the Department of the Gulf, (1866–67).