As you may know, I am writing a novel. It's set in Prohibition America, and is all about the Mafia.

Now, it's 1931 in my novel right now, but the main Mafia Family has the normal rankings as we know them today. I have tried researching, but I find that with this subject you can read totally different things on different sites. Would it be possible for the Mafia to have such rankings as Consigliere and Capo, or did these not come into effect after the Castallemmarese War and the Comission was set up?
Mick