Sometime in the early 1960’s, the US Congress had a public hearing about organized crime. These hearings were on national TV, and featured the testimony of a Mafia guy…one Joseph Valachi. I can remember my dad talking about them-they seemed to go on for a long time.
Anyway, this Valachi told a lot of tall tales about the Mafia-was it found out later that much of his testimony was pure fantasy? Or was this guy telling the truth.
I have one very dim memory of this…at one point, Valachi was discussing the crime family of Joseph Bonanno (who was a major crime boss). Valachi caused the senate to break out in laughter when he mispronounced “Bonanno” as “Bananas”!
Did Mario Puzo incorporate Valachi’s testimony into “THE GODFATHER”?
When did Valachi die? And, was it in bed, or was he “hit” by the Mafia (for talking)? 
I don’t see why they would have laughed at that - Bonanno’s nickname was Joey Bananas anyway…
According to Wikipedia (http://en.wikipedia.org/wiki/Joe_Valachi):
The McClellan Committee hearings (where Valachi testified) were part truth, part stuff Valachi was making up (or had made up for him by Hoover, possibly).
He made Vito Genovese out to be the overarching power in the mafia, when in reality he was merely the strongest of many provincial leaders. Few true Capos di Tutti Cappi ever existed, and Genovese certainly wasn’t one of them (although he tried). In short, Valachi was telling the truth about a lot of general mafia practices, terms, and their total strength and influence. His testimony was nearly useless when it came to specifics and accurate estimates of the power of individuals capos and families.
The McClellan hearings brought down Vito Genovese, and more importantly, led to the 1970 passage of the RICO Act, the anti-racketeering legislation which the Federal Government used to gut the mafia.
Puzo said he based The Godfather on “public sources,” and it seems pretty certain that Valachi was one of those.