As of 2014, Marathon Oil Corporation is a public company, which means it is owned by its numerous shareholders, and has its headquarters in Houston, Texas. Its shares are traded under the symbol MRO on the New York Stock Exchange.
In 1982, Marathon Oil Company became a wholly owned subsidiary of United States Steel Corporation. United States Steel Corporation changed its name to USX Corporation in 1986, which included the Marathon Group and United States Steel LLC. In 2001, the USX Corporation’s Board of Directors voted to separate the Marathon Group and United States Steel LLC and re-establish them as two independent companies. The company was originally founded by Henry Ernst in 1887 and was known as the Ohio Oil Company.