 In the film, it is suggested that Joan Blondells character got the  idea of the numbers racket from her assistant, "Nellie". In reality,  the numbers racket was pioneered by black gambling racketeers in  Harlem. The "Nellie" character was based on Stephanie "Madame Queen"  St. Clair (Nellie scoffs at being called "Madam Nellie"). As in the  film, the numbers racket was eventually taken over by "Dutch"  Schultz and "Lucky" Luciano (The Humphrey Bogart and Barton MacLane  characters, respectively).