"Black" Dance Marathons (continuous motion) or "Derbies" became extremely popular during the depression years (1920s-30s) as many out of work people would compete for money prizes, as well as stars of some kind seeking publicity. The longest running dance marathon lasted for 22 weeks and 3½ days. Dance marathons were eventually outlawed (called Blue Laws) in most states due to the unhealthy condition they would put the contestants in. Link… If you're interested in reading more, here is a link to an excellent thesis [PDF] written by Chelsea Dunlop. There is also this short article from American Heritage [scroll down to 1923 - Can’t Stop Dancin’]: "On April 1 Americans awoke to find their country in the thrall of a brand-new sport: marathon dancing. The fad had begun in England in early March with an effort of nine and a half hours—a virtual sprint. A pair of doughty Scots immediately did fourteen, and within two weeks French dancers had broken the twenty-four- hour barrier. At this point, with events having clearly surpassed the bounds of sanity, it was time for the Americans to step in." more…