United States territorial acquisitions
West Florida was declared to be a U.S. possession in 1810 by President James Madison after the territory had declared its independence from Spain. Madison ordered the U.S. Army to take control. Six weeks later, the army entered and occupied the capital, St. Francisville, putting an end to the republic after 74 days of independence. Spain did not relinquish its claim to sovereignty (see West Florida Controversy) until ratification of the Adams–Onís Treaty. General Andrew Jackson personally accepted the delivery of West Florida from its Spanish governor on July 17, 1821.
Florida
On January 10, 1861, nearly all delegates in the Florida Legislature approved an ordinance of secession, declaring Florida to be "a sovereign and independent nation"—an apparent reassertion to the preamble in Florida's Constitution of 1838, in which Florida agreed with Congress to be a "Free and Independent State." Although not directly related to the issue of slavery, the ordinance declared Florida's secession from the Union, allowing it to become one of the founding members of the Confederate States, a looser union of states.