The Nanny that Nelson hires speaks an accent somewhat resembling Swedish, and the song she sings to the baby is a common Swedish lullaby about a troll and her children.
When Nucky, Torrio and Rothstein are meeting at the army base, soldiers can be heard drilling in the background. Immediately after Rothstein says "I bet it all" someone can be heard chanting the 'Hell March' from the video game Command & Conquer: Red Alert (1996).
Final appearance of actor Tom Aldredge (Nucky's father Ethan Thompson).
When the family is playing the board game they take turns in counter-clockwise order - opposite from how games are generally played.