The boys swordplay book that Emma Harrow gives to Richard is "The Chessmen of Mars," an Edgar Rice Burroughs science fantasy novel, the fifth of his famous Barsoom series. Burroughs started writing it in January, 1921, and the finished story was first published weekly as serial in "Argosy" in six installments from February 18 through March 25, 1922. It was later published as a complete novel by A. C. McClurg in November 1922. It is that novel that Emma gives to her brother.
The Onyx Club was deliberately patterned after Harlem's Cotton Club.
The location for the political rally was shot on location at 54 Port Richmond Avenue in Staten Island, New York at the Reformed Protestant Dutch Church filming dates were July 10-13th, 2013.
Christiane Seidel (Sigrid Mueller) & Erik LaRay Harvey (Dunn Purnsley) also worked together on three episodes of Godless (2017) as Martha & Elias respectively.