Premise: In the American Mafia, a made man is a fully initiated member of the Mafia. To become "made", an associate first has to be sponsored by another made man. An inductee will be required to take the oath of Omertà, the mafia code of silence. After the induction ceremony the associate becomes a "made man", and holds the rank of soldier (Italian: soldato) in the Mafia hierarchy.
Hypothesis: One needs to take the oath of Omerta to join the American Mafia