23 Skidoo
A traveler to the 1920s will have heard the idiom 23 skidoo, but knowledge of its origin would be vague at best. It is commonly attributed to policemen, who ordered idlers on New York’s 23rd street to move along rather than wait on the sidewalk for the winds around the unusually shaped Flatiron Building to cause the skirts of passing ladies to blow up in the air, revealing their otherwise unseen legs. This tale, though amusing, is dubious, since both 23 and “skidoo” were used to order people to move along before the Flatiron Building was built in 1906. The use of both terms appeared in print in the 1890s, and it is possible that 23 was used as early as the 1860s.
23 may have derived from the novel A Tale of Two Cities. When Sydney Carton goes to the guillotine he hears the number called, after which he is gone. A popular play based on the novel was performed in New York in the late 1890s, and the use of 23 in reference to going and being gone emerged around the same time. Skidoo, sometimes spelled skiddoo, most likely derived from skedaddle. The two expressions were used in a play by George M. Cohan in 1904, and in advertisements as early as 1906, so though the diligent cops protecting the virtue of lady pedestrians may have shouted the phrase in the 1920s, it didn’t originate with them.