In several texts you'll also find the name Billy LaShade which, as is often the case in traditional folk music, just adds a little spice and confusion to the mix. The name could be the author's, also could have been a minstrel who made it popular in his region. Check out H.M.Belden's "Ballads & Songs" collected by the Missouri Folklore Society. This is a great source for Missouri songs & ballads, also discusses authorship, not in depth but in passing of Jesse James. They don't much credence to old Billy Gashade.