Archibald "Water" Mellon was the third son of former treasury secretary Andrew W. Mellon. Not sure if there's any relation to Thornton Mellon, who was portrayed by Rodney Dangerfield in the biopic "Back to School". It's disputed by historians whether the nickname "Water" Mellon was a play on the popular botanical fruit, or if it refers to Mellon being a noted boating enthusiast of his day.
"...the successful annihilation of organized crime's subculture in America would rock the 'legitimate' world's foundation, which would ultimately force fundamental social changes and redistributions of wealth and power in this country. Meyer Lansky's dream was to bond the two worlds together so that one could not survive without the other." - Dan E. Moldea
