I think Uncle Dave Macon did "Hold the Woodpile Down" way before Doc - back in the late 1920's. As a kid, Uncle Dave lived in a boarding house which catered to vaudeville people. That's supposedly where he got his minstrel oriented material. Doc has covered a lot of the great old tunes from Uncle Dave, Charlie Poole, etc.

You could probably ask a similar question about "Shenandoah" (The Wide Missouri)with its combination of middle-American indian maidens, trappers, and then the odd seaman type verses. Folk songs move, who knows which way - sea to land, or land to sea ??