"One of the popular New York City myths is that the slang term "twenty-three skidoo" comes from the Flatiron Building at Twenty-Third Street and Broadway/Fifth Avenue. Tourist buses pass by this spot; they have to talk about something. The area has high winds, lifting women's skirts up. Allegedly, an Officer Kane told some naughty boys to "twenty-three skidoo" from the scene. Scram! Beat it! Go away! The problem here is that I've found articles about "twenty-three" in 1899. The Flatiron Building was completed in 1902. One theory is that "23" is the number of the last victim in the then-popular play version of Charles Dickens's novel A Tale of Two Cities, titled The Only Way. "Skidoo" probably comes from "skedaddle," a term made popular during the Civil War. I have several articles that credit the vaudeville actor Billy B. Van with combining the two slang terms into "twenty-three skidoo." No doubt, the slang phrase was popular. No doubt, it was used at 23rd Street."