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.
History of Alabama
More than a decade later, during the American Revolutionary War, the British informally ceded this West Florida region to Spain. By the Treaty of Versailles, September 3, 1783, Great Britain formally ceded West Florida to Spain. By the Treaty of Paris (1783), signed the same day, Britain ceded to the newly established United States all of this province north of 31°N, thus laying the foundation for a long controversy.
By the Treaty of Madrid in 1795, Spain ceded to the United States the lands east of the Mississippi between 31°N and 32°28'N. Three years later, in 1798, Congress organized this district as the Mississippi Territory. A strip of land 12 or 14 miles wide near the present northern boundary of Alabama and Mississippi was claimed by South Carolina, as part of the eastern colonies' previous hopeful extensions to the west. In 1787, during constitutional negotiations, South Carolina ceded this claim to the federal government. Georgia likewise claimed all the lands between the 31st and 35th parallels from its present western boundary to the Mississippi River, and did not surrender its claim until 1802. Two years later, the boundaries of Mississippi Territory were extended so as to include all of the Georgia cession.