John D. Rockefeller
Getty Images-Net worth: $340 billion Source of wealth: Oil Lived: 1839-1937 Tycoon John D. Rockefeller brought on a new era of wealth in America, where he nearly
monopolized the oil industry in the late 1800s. The famous New Yorker founded the Standard Oil Company in 1870, capitalizing on a time when soaring demand for
kerosene and gasoline grew Rockefeller’s fortune. He became so wealthy that he left his company in 1897 and spent the last 40 years of his life retired. In his later
days, Rockefeller endowed much of his fortune to schools and medical research, and founded the University of Chicago.
