Here's a thought for the western angle. Having done some rowing it strikes me that this song could set a pace for rowing. So, could the song have travelled from the sea up the Mississippi and Missouri with the keel boats of the fur trade. These boats were, polled, rowed, sailed and towed up river. Likely some of the men were sailors, and no doubt some were Irish. That COULD explain the MIssouri. Then, of course, there are the barges of the eastern waterways and some of those men seem to have come from the canals and "waterman" background of England.One such fellow ended up here in the goldrush of 1862 in B.C. On the English census his water was listed as a "waterman".