"My Sweetheart's the Mule in the Mine"is an example or "horizontal distribution" in oral tradition, this short ditty is widely known but the source is untraceable.
It's good for a laugh at a jam.
It has been printed in Pete Seeger's The Bells of Rhymney and Alan Lomax's The Folk Songs of North America. Lomax credits G. G. Korson's Minstrels of the Mine Patch (1927) as his source.
This version is a combination of Seeger's and Lomax's versions.