Marathon Oil Corporation operates as an energy company in the United States, Equatorial Guinea, the United Kingdom, and Libya. It operates in two segments, United States and International. The company engages in the exploration, production, and marketing of crude oil and condensate, natural gas liquids, and natural gas; and the production and marketing of products manufactured from natural gas, such as liquefied natural gas and methanol. As of December 31, 2018, it had estimated proved developed reserves totaling 752 million barrels of oil equivalent (mmboe); and estimated proved undeveloped reserves totaling 529 mmboe. The company was formerly known as USX Corporation and changed its name to Marathon Oil Corporation in July 2001. Marathon Oil Corporation was founded in 1887 and is headquartered in Houston, Texas.