Frequently designed in collaboration with fellow Pennsylvanian William Park "Billy" Bell, much of Thomas's work is to be found in Los Angeles and southern California. Thomas's best known designs, include but are not limited to:
Riviera CC (1926) / Bel-Air CC (1926) / Los Angeles CC (1927, redesign of North course) / Ojai Valley Inn (1923) / Palos Verdes GC, LA (1924) / Stanford University GC (1930) / Griffith Park, LA (1923, Harding course; 1927, Wilson course). All the above courses are in California.

Born in 1873, Thomas grew-up in Philadelphia, where he graduated from the University of Pennsylvania before joining his father in the investment bank Drexel & Company. As a very competent golfer, he also developed a keen interest in course design and the prevailing "Philadelphia School" of golf course architecture.

After the First World War, in which he served and attained the rank of Captain, Thomas moved to California in 1919. It was here that his flair for course design really took hold. He struck-up a working relationship with William Park "Billy" Bell, with whom he co-designed many renowned southern California courses. Thomas considered the layout at Riviera Country Club to be his masterpiece ... the only one of his courses that has not been substantially altered.

In 1926 Thomas published his seminal book "Golf Course Architecture in America", in which he advocated the use of wide fairways and providing options for golfers to shape their shots. He also believed that hazards were important but should not “unduly penalize or make it hard to recover.” Above all, Thomas thought a golf course should blend into its natural surroundings and provide a layout based on diversity and memorability.