After Britain gained just about everything east of the Mississippi as a result of the French and Indian War, the boundary of West Florida was moved up to 32 degrees, 28 minutes north. When Spain reclaimed Florida, including West Florida, after the Revolutionary War, Spain accepted the then almost 20 years old British definition of West Florida. Of course, as part of the Treaty of Paris (1783), Britain and the U.S. agreed that the boundary of Florida would be at the 31st parallel. Thus we have the U.S.-Spain disputed region of West Florida, finally resolved in the Pinckney Treaty of 1795. This map captures the problem, along with a lot of other good stuff. (If you poke around the northeast portion of the map, you will find the location of Fort William Henry, where, in the summer of 1757, over 12,000 French and Indians under Montcalm besieged and overwhelmed the 2,000+ British garrison. This story was told in Cooper's 1826 book, The Last of the Mohicans.)