Carole Radziwill opened up about her "last summer" with close friends John F. Kennedy Jr. and Carolyn Bessette-Kennedy in the gripping CNN docuseries American Prince. The three-part series revolved around John's lifelong struggle with his family's legacy as well as his whirlwind courtship and marriage to Carolyn before they died in a 1999 plane crash near Martha's Vineyard. (Carolyn's sister Lauren Bessette was also killed in the crash).