From an 1859 song, it's a nickname for the Old South
The train's 
engineer, a thirty-three-year-old named Joseph Steve Broady, had... [DOC] [TLE] The Big Apple: Dixie or Dixie's Land (1859) - Barry Popik [PAR] Dec 25, 2004 ... "Dixie" came to mean the South, and the song was played often by the ... A 
published explanation in 1861 stated that there was an old slaveholder in 
Manhattan ... Dixie is a nickname for the Southern region of the United States.