In 1870, John D. Rockefeller united competing oil companies to create The Standard Oil Company, and by 1880, he had a 90% monopoly on the industry. He became the wealthiest man in modern history (accounting for inflation, he was richer than even Jeff Bezos is today). In 1911, citing the Sherman Antitrust Act, the feds ruled his empire illegal, and Standard Oil was broken up into over 30 entities, among them those that became Exxon, Amoco, Mobil and Chevron.