Real life gangster Arnold Rothstein would later be immortalized in F. Scott Fitzgerald's famous novel 'The Great Gatsby' where Gatsby introduces the narrator, Nick, to a friend and business associate of his called Meyer Wolfsheim, a Jewish gangster and gambler who had 'fixed the World Series,' a roman a clef for Rothstein, who did in real life.
Martin Scorsese encouraged the actors to improvise lines on set, something that is typical of his directing style but very rare on scripted television in which the shooting schedule is typically very strict, and in which the writer is usually outranks the director.
Jimmy Darmody refers to his young son as "Skeezix," who was a character in the comic strip "Gasoline Alley," the second longest-running comic strip of all time. It was conceived and debuted in 1918 in order to communicate information about the the then new phenomena of automobiles. Each strip was meant to communicate useful information to its readers. It holds the distinction of being the first comic strip which had characters who aged.
The Sophie Tucker recording of "Some of These Days," which plays over the scene where Nucky looks in on the baby incubator store front, would have been nine years old at the time the events in this episode take place (it was recorded in 1911).