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.
Florida Parishes
Following the American Revolutionary War, West Florida was the subject of a border dispute between the newly-formed United States and Spain, which acquired West and East Florida from the British after the war. The dispute led American and British settlers in the part of West Florida west of the Perdido River to declare an independent Republic of West Florida in 1810 and elected their leader, Fulwar Skipwith, as president. (None of the short-lived Republic of West Florida lay within the boundaries of the modern state of Florida.) The flag of the Republic of West Florida, which is often identified with the Bonnie Blue Flag of the Civil War era, flies on many public buildings in the Florida Parishes. In 2006 the state legislature designated it the "official flag of the Republic of West Florida Historic Region."