Welby Van Horn's career as a coach has spawned institutions such as the Welby Van Horn Tennis Academy in Boca Raton, Fla., and Welby Van Horn tennis programs in a number of locations. The teaching system he developed is still used today and it is featured in his book "The Secrets of the Tennis Master."
Van Horn was a star player and contemporary of other world-class players and USPTA members, including Fred Perry, Bobby Riggs, Bill Tilden, and Bruce Barnes. When he was 19 years old, he reached the finals of the 1939 U.S. Nationals. A highlight of his playing career was his crushing defeat of the great Bill Tilden during a match between U.S. and British Empire service teams at Wimbledon in 1945. Van Horn also won the United States Pro Championship (a USPTA event) in 1945.