The term "Dixie" comes from the time of the founding of New Orleans (New Orleans). This city was the main commercial and financial center in the region, and many banks issued their own notes (with the name of the bank - was legitimate at that time). These were printing in French or in English with bilingual too, and one of the most common names was the ten-dollar bill.
Now "ten" in French is nothing more than "Dix," a word that was printed in large letters on the back. After purchase of the state of Louisiana by the Americans to the French in 1803, and as more and more Americans moved to the area, they came as the "Dixie".
Only a note had value since the bank accepted it, as many of the most reliable banks were in New Orleans, "Dixie" was the note of preferred stock for a long time and by most local residents. The region itself became associated with the word Dixie became the land of Dixie, ie "Dixieland".