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.
West Florida Controversy
In 1810, a group of discontented American and British settlers in the area of Baton Rouge learned that the Spanish colonial governor, who had feigned sympathy, was in fact mounting a force against them. They revolted by overrunning a Spanish garrison at Fort San Carlos in Baton Rouge on September 23, 1810, and declared the independence of the Republic of West Florida on September 26. On October 27, the United States president proclaimed that the territory should be annexed, and Spain, then embroiled in the Peninsular War with France, could do little to resist. On December 10, the United States military completed the forcible occupation and acquiescence of the Republic of West Florida.