I’m a former employee of the Rock Island RR and subscribe to an email discussion list about the RR.  Some posts came through claiming that the origins of the song “Wabash Cannonball’ are in another song “The Great Rock Island Route.”
 
Here is a link to a Wikipedia article supporting the claim: https://en.wikipedia.org/wiki/Wabash_Cannonball
 
Here is a link to the original song lyrics (with a download link): https://levysheetmusic.mse.jhu.edu/collection/057/135