ExxonMobil, an American multinational oil and gas corporation presently based out of Texas, has had one of the longest histories of any company in its industry. A direct descendant of John D. Rockefeller's Standard Oil, the company traces its roots as far back as 1886 to the founding of the Vacuum Oil Company, which would become part of ExxonMobil through its own merger with Mobil during the 1930s. Today, the company, which merged from Exxon and Mobil in 1999, is the largest investor-owned oil and gas company in the world by revenue and market capitalization.