Dance marathons were a phenomenally popular fad during the manic 1920s and depressive 1930s. What began as a craze soon developed into a money-making business which lasted 30 years. Some 20,000 contestants and show personnel participated in these events; audiences, the majority women, totalled in the millions. "A Poor Man's Nightclub," dance marathons were the dog-end of American show business, a bastard form of entertainment which borrowed from vaudeville,...