"Tom -
Yes, that is the question.
First, what professional architects worked in the US between 1900 and 1910? Even Ross didn't view himself at that time as a professional archie. That came a couple of years later. Was Tillie working that early? I'm having trouble visualizing the pool of available "professional" talent circa 1905. Or if there even was a pool."
Bob:
That's an excellent question and obviously a good place to start. It hadn't exactly occurred to me but this most certainly is a very important question if we are going to attempt to track the history and evolution of American golf course architecture. Perhaps we should begin to construct our lists that reflect as best as can be known who it was exactly who worked professionally over here in the 1890s, 1900s, and even into the teens. Maybe the best method would be to just go through C&W alphabetically and see who comes up from that. I think we will find all the "usual suspects" of immigrant Scottish, English or even Australian player/pro/greenkeeper/club-maker/teacher/architects.
Here they are out of C&W:
Herbert Barker
Tom Bendelow,
Harry Collis,
George Cumming,
James Dagleish,
Seymour Dunn,
John Duncan Dunn,
Willie Dunn Jr,
Willie Davis,
Devereux Emmet,
Arthur Fenn,
Alex Findlay,
James Foulis,
Robert Foulis,
Walter Fovargue,
Robert Johnstone,
George Low Sr,
Norman MacBeth,
Charles Maud,
George O’Neil,
John Park,
Willie Park Jr,
Robert Pryde,
Donald Ross,
Herbert Strong,
A.W. Tillinghast,
Walter Travis,
William Tucker,
H.J. Tweedie,
Willie Watson,
Bert Way,
Robert White,
George Wright.
All the foregoing apparently did architecture professionally in the teens or before in America.
“Second, and the real question, is what influenced the good amateur designers? What distinguished them from other local enthusiasts who built the other 1,000 courses of the era that have since sunk into oblivion?
Good question. Hard question. Big question.”
They certainly are good questions, Bob.
It seems to me one of the primary things that influenced those great early “amateurs” who produced the great courses mentioned above is just about all of them took the time early on to go over and study the linksland and particularly the early heathland architecture before launching into their projects which were notably very limited in number.
And I think the thing that distinguished most of the foregoing early “amateurs” mentioned above who produced such great courses from the early professionals mentioned above was simply that almost none of those professionals spent anywhere near the amount of time on their projects that all those early “amateurs” mentioned above did.
We are generally probably talking a few days or weeks at most with the early professionals compared to literal years or even decades for those early "amateurs" mentioned above.