What do you think was the major impact of the United States buying Florida from Spain?

That I don't think it was really fair because the Spanish minister Do Luis de Onis and U.S. Secretary of State John Quincy Adams sign the Florida Purchase Treaty, in which Spain agrees to cede the remainder of its old province of Florida to the United States. ... Florida was organized as a U.S. territory in 1822 and was admitted into the Union as a slave state in 1845.