Factual error: The movie takes place in the summer of 1922. They played Rhapsody in Blue, which wasn't written till 1924. The bandleader is obviously Cab Calloway. Cab Calloway's first recordings with the Missourians weren't until 1928. "Oh! You Have No Idea" also wasn't recorded until 1928, and it was sung by Sophie Tucker, not Josephine Baker (although they do credit Ms. Tucker in the final credits).
Factual error: Trains of various types appear in several shots but the trains shown - likely all CGI - are completely unlike any trains that were in use in New York in the 1920s or in any other era. They appear to be based on Australian prototypes and their design differs significantly from American trains.