Exxon is an American multinational oil and gas corporation. It was founded in 1870 by John D. Rockefeller as the Standard Oil Company and was the world's first vertically integrated oil company. In 1999, it merged with Mobil to become ExxonMobil, the world's largest publicly traded oil and gas company. ExxonMobil is one of the world's largest publicly traded companies and is a major player in the global energy market.