Exxon Mobil is the world's largest private oil and petrochemical company and a leader in the global oil and gas field. It began with the Standard Oil Company founded by John Rockefeller in 1882 and is headquartered in Texas, USA. Aiwen City. ExxonMobil was also the first company in the world with a market capitalization of over US$400 billion, ranking first among the Fortune 500 in 2006.