Ed:
Macdonald's interest in golf (and perhaps the emanation of design) began when he was sent from Chicago to college at St Andrews University in the early 1870s. There he was first introduced to golf, completely fell in love with it and got quite good at it in a short time.
He returned to America to Chicago after that and entered into what he referred to as his "Dark Age" in golf. What he meant by that is there were no golf courses in America then (to speak of), no golfers, no balls or equipment and for almost twenty years he really didn't or couldn't play golf basically for those reasons, not to mention the fact no one was interested in it because no one over here really knew it.
All that changed during the amazing Columbian Exposition in Chicago in 1893 (World Fair). A bunch of Brits came to it with their clubs and he claims they lit the spark for golf with him at that time in Chicago (he had laid out a rudimentary seven hole course in Lake Forest in the spring of 1892). From that he generated some golf interest in Chicago and laid out a course at Belmont and then the first 18 hole golf course in American, the Chicago Golf Club in 1895 in Wheaton.
You can find more detail in the chapter "Beginning of Golf in America" in his 1928 biography, "Scotland's GIft Golf."
Yeah, Ed, you do need to read that book to appreciate that even though Macdonald was by no means the first man to introduce golf to America he probably was its most important over-all participant in those early years for the simple reason he got into every single aspect of it more than anyone else had before or did at that time.
In 1900 he moved from Chicago to New York, quite quickly got the idea to build an ideal American course (which became NGLA) and the rest, as they say, is history.
By that time he was well known by that time as the first US Amateur champion, he had been one of the original vice presidents of the USGA (he proposed it should be formed) and with his connections abroad sort of a "go to" guy for golf organizational administration, tournaments, the Rules of the Game, and also an authority on golf architecture.
By the way, one could not technically say Macdonald was in the business of golf in any way or ever. He was always very much the inveterate and traditional "amateur/sportsman", with a real highlight on "amateur" and he always steadfastly refused to take any money for anything he ever did with or around golf or for golf.
I'm not sure one could say Macdonald necessarily had something against commercialism in golf or professionalism in golf but there isn't much question he certainly never saw a roll for himself in golf like that.