The same year that "The Black Crook" opened, "The Black Domino/Between You, Me and the Post" was the first show to call itself a "musical comedy". In the late 1860s, as post-Civil War business boomed, there was a sharp increase in the number of working- and middle-class people in New York, and these more affluent people sought entertainment. Theaters became more popular, and Niblo's Garden, which had formerly hosted opera, began to offer light comedy. "The Black Crook" was followed by "The White Fawn" (1868), "Le Barbe Blue" (1868) and "Evangeline" (1874). An apparently similar show from six years earlier, "The Seven Sisters" (1860), which also had an unusually long run of 253 performances, is now lost and forgotten. It also included special effects and scene changes. Gänzl gives "The Naiad Queen" (1841) as an example of an earlier musical, concluding that it was only "The Black Crook's" long run that gave it a reputation as the "first" musical. Theatre historian John Kenrick suggests that "The Black Crook's" greater success, compared with earlier shows, resulted from changes brought about by the Civil War: First, respectable women, having had to work during the war, no longer felt tied to their homes and could attend the theatre, although many did so heavily veiled. This substantially increased the potential audience for popular entertainment. Second, America's railroad system had improved during the war, making it feasible for large productions to tour.