John H. Davis 


John Hagy Davis (June 14, 1929 – January 29, 2012) was an American author who wrote several books on the mafia. 

Davis was the son of stockbroker John E. Davis and Maude Bouvier, younger sister of John Vernou Bouvier IIIand therefore first cousin of Jacqueline Kennedy Onassis and Lee Radziwill. He was a graduate of Princeton University. He also studied in Italy and served as a naval officer with the Sixth Fleet in the Mediterranean. He is the author of several books about notable American families such as the Bouviers, the Guggenheims and the Kennedys.