Lafayette County was created in 1856 from part of Madison County. At the time it comprised all the area of present-day Lafayette and Dixie counties. The County was named in honor of the Marquis de Lafayette, the French general who rendered assistance to the Continental Army in the American Revolutionary War. The county seat is Mayo. The locals pronounce it La-FAY-ette, with a long A, like Fayetteville, Arkansas. The Suwannee River forms the entire eastern boundary. The county has a total area of 548 square miles, of which 543 square miles is land and 4.5 square miles (0.8%) is water.