History of Florida
In 1810, parts of West Florida were annexed by proclamation of President James Madison, who claimed the region as part of the Louisiana Purchase. These parts were incorporated into the newly formed Territory of Orleans. The U.S. annexed the Mobile District of West Florida to the Mississippi Territory in 1812. Spain continued to dispute the area, though the United States gradually increased the area it occupied.Seminole Indians based in East Florida had been raiding Georgia settlements, and runaway American slaves were their allies; Negro Fort, an abandoned British fortification in the far west of the territory, was manned by both Indians and blacks. The United States Army would lead increasingly frequent incursions into Spanish territory, including the 1817–1818 campaign against the Seminole Indians by Andrew Jackson that became known later as the First Seminole War. The United States now effectively controlled East Florida. Control was necessary, according to Secretary of State John Quincy Adams, because Florida had become "a derelict open to the occupancy of every enemy, civilized or savage, of the United States, and serving no other earthly purpose than as a post of annoyance to them." Florida had become a burden to Spain, which could not afford to send settlers or garrisons. Madrid therefore decided to cede the territory to the United States through the Adams–Onís Treaty, which took effect in 1821.
The Floridas
The Floridas was a region of the southeastern United States comprising the historical colonies of East Florida and West Florida. The borders of East and West Florida varied. In 1783, when Spain acquired West Florida and re-acquired East Florida from Great Britain through the Peace of Paris (1783), the eastern British boundary of West Florida was the Apalachicola River, but Spain in 1785 moved it eastward to the Suwannee River. The purpose was to transfer San Marcos and the district of Apalachee from East Florida to West Florida. From 1810 to 1813, the United States extended piecemeal control over the part of West Florida that comprised the modern-day Gulf coasts of Alabama and Mississippi and the Florida Parishes of Louisiana. After the ratification of the Adams-Onis Treaty in 1821 the United States combined East Florida and what had been the remaining Spanish-controlled rump of West Florida into the territory that comprised modern-day Florida.