"Earliest date: 1966" !?

I remember singing this in my 4-H club about ten years earlier than 1966. And we sang it off yellowed, mimeographed sheets that probably dated to the late medieval period.
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"Belden refers to a 17th c. broadside, "The Seaman's Complaint," "printed for Charles Baker" (British Museum C. 22, f. 14, p. 175)."

Does it seem to you that some folklorists are trying awful hard to link songs that have no connection? So a cowboy song and a broadside both tell of a man who is discontented and plans to move along. That has probably happened millions of times in history, and it doesn't mean the songs are related.