(Is "Golden Era" post WWI?)
Definitely a Chicago-centric answer, but I would say Herbert J. Tweedie.
Tweedie laid out some incredible courses that were subsequently "redone" by Flynn, Ross, Langford, CBM, etc.
Thanks, Dan Moore, for the following:
"In Cornish and Whitten’s “The Golf Course”, Tweedie was credited with laying out the following courses: Belmont, Bryn Mawr, Exmoor, Homewood (now Flossmoor), Glen View, LaGrange, Midlothian, Park Ridge, Hinsdale, Rockford, Washington Park, Westward Ho, Maple Bluff, and a remodel with James and Robert Foulis at Onwentsia.
The work on the nine hole Belmont Course in 1892 became the original location of Chicago Golf Club, of which Herbert was a founding member. When the Chicago club moved to Wheaton in 1894, he built a new course at the Belmont links and became the club’s president for three years."