The trouble with long threads is that people will post to them without bothering to read them first. Just occasionally they will add new and useful information, but usually they just repeat what has already been said; and that will often, as in the case of "hawkerlad", who revived the thread this time round, mean repeating -as fact- romantic assertions for which there is not, so far as can be told, a shred of evidence. Then, in turn, others must repeat such accurate details as have already appeared, and so it continues in interminable and ever more confusing circles.
My link to the late Bruce Olson's material on the song, given above (some years ago) no longer works; since his death, it has been archived at the University of Fresno (and at Mudcat, but that is not always working). See instead
for the most accurate information on the history and background that you are likely to find online; or, perhaps, anywhere else. Bruce was a considerable scholar, far exceeding anyone else represented in this old thread.