Rockefeller's Standard Oil used to be the most profitable company in the world. What happened to it?
It was forcily split to several independent companies. In 1911, the Supreme Court of the United States ruled that Standard Oil must be dissolved under the Sherman Antitrust Act and split into 34 companies. Four of these companies were "Jersey Standard", which became Exxon, "Standard Oil of New York" which became Mobil, "Standard Oil of Ohio" which became SOHIO, "Standard Oil of Indiana" which became Amoco and "Standard Oil of California" which became the Chevron Corp.