Thank you JJ and Red Roger for your posts on this thread. I will have a look at the reference given.
JJ, I, too, found a photograph on one of the sites that was basically an obituary posted by the husband of one of Harry's descendants. As soon as I saw it I 'just knew' he was the man I had been looking for as the resemblance to my father was uncanny. I emailed the poster and eventually was put in touch with two 'half aunts' living in the US. They were able to fill in some of the detail following Harry's move to the US. We have exchanged photographs and information, which was brilliant. I understand from them that they weren't terribly surprised to discover his previous marriages, (my Grandmother was number two on the list). I have half an idea that he was still married to wife number one when he married in the US. I would have liked to have known what had happened to Jessie, but picking up her trail from all that time ago was a bit of a non-starter. I think Jessie was the one I felt most sorry for, losing her son at an early age and then Harry "re-marrying" within a few weeks of that child dying.
Yes, I too wonder why some men walked down that particular path.
Thank you again to all who have replied and have offered help in this "quest",
Regards to all
Siouxie