There was an uneasy alliance between amateurs and professionals in American tennis during the 1940s. The conservative, upper-class traditions of the sport were protected by the United States Lawn Tennis Association (USLTA), a member of the International Lawn Tennis Association (ILTA), which provided standardized rules throughout the world and declared itself an organization of amateurs only. Professional tennis coaches began to appear in the 1920s, and they had formed an alliance called the Professional Lawn Tennis Association (PLTA) to declare their adherence to USLTA standards, even though they charged to teach tennis. In 1928 the Palm Beach Tennis Club staged the first exhibition by professional tennis players, many of whom were PLTA members, but the event did not stimulate much enthusiasm. By the 1940s there were touring professionals who played for small audiences — the Bill Tilden tour,was the most successful — and the USLTA...