William Flynn's clients at the following courses represented a significant cross-section of American aristocracy:
Shinnecock Hills: Juan Trippe, chairman of Pan American Airways helped to convince the president of the club, Lucien Tyng, to hire Flynn to completely redesign the golf course after Tyng bought an additional 108 acres north and east of the clubhouse.
Pocantico Hills: After a long search, the contract to redesign the golf course at the Rockefeller estate in Tarrytown, NY came down to 2 men; Donald Ross and William Flynn. Mr. Rockefeller, Jr chose William Flynn in part due to the success of the redesign of Shinnecock Hills. We have a large amount of correspondence between JDR, Jr and Flynn. Rockefeller was intimately involved in the smallest details of the course being built for his father. After completion, Flynn was involved in landscape design for the estate.
Addison Mizner: Donald Ross was building the Cloister Inn golf course for Mizner's new city of Boca Raton. Part of this large land plan was a Ritz Carlton resort hotel. Wm. Flynn was chosen to design 2 courses for the Ritz. The land bust, 1926 hurricane, and the subsequent stock market crash ensured that the project would not be completed. Mizner lost his fortune and several others in this venture.
Clarence Geist: One of the richest men in America through his extensive utility holdings, Clarence Geist hired Hugh Wilson to design the original Bay Course at Seaview near Atlantic City, NJ. A second 9-hole couse was added known as the Pines. Today's Flynn holes are the first 2 holes of the Pines 18-hole course along with the current 12-18. When Geist bought the Boca Raton development project from a bankrupt Addison Mizner, Geist hired Flynn to design the NLE Boca Raton North and South courses. Geist, in a letter to Lucien Tyng said he would never build another golf course without Flynn as the designer.
Albert Lasker, the pioneer advertising magnate out of Chicago built an estate course, Mill Road Farm, that was considered one of the most challenging golf courses in America. Originally opened as a 7000 yard par 72 or 71 course in 1926. Many top professional golfers tried over the years to break par. It was finally accomplished by the great Tommy Armour.
Flynn designed a private estate course for Robert Cassatt, president of the first billion dollar company in the world, The Pennsylvania Railroad. Cassatt was the nephew of the famous impressionist painter, Mary Cassatt.
The Brahmins and sporting elite of Boston were well-served by their native son. Flynn added nine holes and did significant work on the original 18 of The Country Club in Brookline. Probably as a result of this effort, Flynn got the job to design The Kittansett Club for utility tycoon Frederick Hood.
Princeton University hired Flynn to redesign the college golf course.
Perhaps the most elite founding membership of all time, that of The Creek Club, hired Flynn to propose changes to the Macdonald/Raynor course after having numerous flooding problems on the "water holes." Thankfully, few changes were implemented thus saving the 10th and 11th (Biarritz) holes. Flynn may not have desired to obsolete the holes entirely, but he did propose new 16th and 17th holes on land adjacent to the 17th green and 18th fairway. It could be that these holes were intended to be used and the routing progression altered when the water holes flooded.