Marathon is the name of an oil company founded in 1887 as "The Ohio Oil Company" of Lima, Ohio. In 1889, like many other oil interests of the day, it was acquired by John D. Rockefeller's Standard Oil Company. In 1911 after the U.S. Government-ordered breakup of Standard Oil under the Sherman Antitrust Act, Ohio Oil once again resumed operation as an independent entity.
The company was greeted with tremendous success over the years, expanding its business interests both nationally and internationally. In 1962 the Ohio Oil Company changed its name to "Marathon Oil" in an effort to present a more global image.
In more corporate moving and shaking, Marathon Oil merged with U.S. Steel in 1982 to form the USX-Marathon Group only to split with U.S. Steel again twenty years later on January 1, 2002 and officially re-assume its identity as the Marathon Oil Corporation.
Today Marathon is a large player in international oil and gas exploration and production. It has oil reserves of over 1.2 billion barrels. Through its 62% stake in Marathon Ashland LLC it also operates seven refineries and over 6,000 commercial gas stations throughout the United States (familiar brands include Speedway SuperAmerica). The company is based in Houston, Texas and employs over 4,000 people worldwide. It generates nearly $7 Billion in revenue annually.
Sources: marathon.com, hoovers.com, Yahoo! Finance