Jeffrey:
I'm not sure what you're referring to when you say Willie Campbell embarrassed Open winners by challenging them or that he may've been relegated to a public course (I suppose you mean what he did with Franklin Park).
Those early exhibition matches between the good early Scottish professionals in America beginning in the early 1890s were actually the events which served to truly spark interest in the game of golf with Americans. They afforded the opportunity for those who were first learning the game over here to see how it was played by the best.
And as far as Campbell being relegated to a public course (Franklin Park) I seriously doubt that. Obviously Campbell was a guy who was doing all kinds of things with golf following his arrival in the spring of 1894 and up until he died young in 1900 (aged thirty eight or so). There is no question in my mind that when we was encouraged to come over here (presumably by Washington B. Thomas of The Country Club) it would've been natural for Thomas and his friends in early golf in Boston (the likes of Laurence Curtis, Hunnewell, Bacon, Windelar, Leeds, Appleton etc, etc) to help the guy out by using him and his services such as to teach the game, perhaps supply clubs and balls and do some golf architecture as well as playing exhibitions with other really good Scottish immigrant professionals.
I cannot imagine that Campbell could've been able to do what he did with the numerous clubs he had something to do with or even Franklin Park without the help, politically and financially, of the people in Boston who were socially powerful back then and newly interested in golf. All those people from the early clubs of TCC, Essex, Myopia etc knew one another anyway. And actually many of those prominent early golfers at those clubs used Franklin Park anyway and almost to the exclusion of others they used it so much in the beginning.
And then there is the incredibly interesting story about Campbell's wife, Georgina! She came over here a few years after Willie but her story and history with golf in this country is incredible in a specific aspect----eg she survived Willie by nearly fifty years, she may've been the first woman professional in this country, and perhaps in the world, she ran Franklin Park for years, she was a constant and excellent teacher and one could not possibly deny that the woman was truly loved and admired in golf around Boston for many years.
If American golf and particularly American woman's professional golf has a true "God Mother," in my opinion, and in the opinion of others, it would very arguably be Willie Campbell's wife and widow, Georgina Campbell.