How come the lyrics of the song differ so much?

genuinely astonishing that we have a song form over a hundred years ago just astonishing 

it's so crazy that we have this song from over a hundred years ago. They shall not grow old is a master piece  

Hanging On The Old Barbed Wire

I Wish I Was In Dixie Land ( Confederate Anthem )

I had to slow it down by 6% to avoid copyright.
Enjoy the song without Soundcloud Go!