A Chernow tome. This biography isn‘t imaginative but it lays out an account, possibly exhaustive, of the U.S.‘s one time richest person. It explores John D Sr.‘s roots, including the roles of his bigamist peripatetic father and his stolidly Baptist mother; his gift for accounting and insistence on deriving value in every transaction; his conquering of the world‘s refined oil market; through to his early retirement and revolution in philanthropy.