Tompkins owned and trained Rossfenton who in 1910 won the most prestigious steeplechase event in the United States, the American Grand National.
For 1925, Gwyn Tompkins was the United States Champion Thoroughbred Trainer by earnings.
A story in the November 1, 1925 issue of the Chicago Daily Tribune was headlined: America's Leading Race Trainer Near Death at Laurel.
[2] Tompkins recovered from his illness but five weeks later the New York Times reported that he had resigned as trainer for Glen Riddle Farm due to his health problems.
A resident of Warrenton, Virginia where Mrs. Sloan maintained her stable, in November 1938 the then seventy-seven-year-old Gwyn Tompkins took a heavy fall on ice and died in hospital as a result of his injuries.