Try looking at the closing credits to "I am Number Four"!!!
It is also featured in the following--
Chat with our AI personalities
Song of the south 1946
SUR
a song sung by Matt monroe
Most recently in the film "Anchorman: The Legend of Ron Burgundy " with Will Ferrell . . . although the cast was singing the song.
It is a civil war era version of a much older Irish ballad, "The Girl I Left Behind Me". It also seems to be somewhat colloquialized (Either to post Civil War Missouri, or perhaps to the screenwriter's idea of post Civil War Missouri...) as I cannot find the exact lyrics on the web. I also recall a version of this song being featured in at least one John Wayne cavalry western.