Dixie was actually writen by a Northerner (from Ohio nonetheless)
There are a number of conflicting legends about the origin of the tune "Dixie". The man credited with the tune, which went on to become the favorite marching song of Confederate forces during the Civil War, was Daniel D. Emmett, an Irish American originally from Ohio. Emmett played the violin with a minstrel troupe which performed regularly in an auditorium which would later be called Mechanics Hall, located in lower Manhattan. He composed the song on September 11, 1859.