Former

Predecessor company

The predecessor company of Marathon Petroleum Corporation, Marathon Petroleum Company LLC, formerly known as Marathon Ashland Petroleum LLC, was formed by the merger of the refining operations of Marathon Oil and Ashland Inc. in 1998.^[16] The merger brought together several descendants of the Standard Oil trust, as Ashland had acquired several smaller Standard spinoffs while Marathon itself was directly owned by Standard Oil. It also brought Marathon's Speedway and Ashland's SuperAmerica convenience store chains together and were subsequently merged as "Speedway SuperAmerica".

As longtime Marathon rivals Standard Oil of Ohio and Amoco were acquired by British company BP, Marathon Ashland adopted the marketing slogan "An American Company Serving America", with the slogan being adjourned to Marathon gas pumps. In 2006, it adopted its current slogan, "Fueling the American Spirit" as the company shifts emphasis on work ethic and the contributions of its employees.^[17]

In 2005, the company became a 100% owned subsidiary of Marathon Oil, after Ashland sold off its downstream assets and exited the retail business.^[18] In 2006, Marathon began using STP-branded additives in its fuel.^[19]

In 2009, the company completed a $3.9 billion expansion of its refinery in Garyville, Louisiana, that increased the plant's capacity by 180,000 barrels per day.^[18]

In 2010, the company sold its 74,000 barrel-per-day refinery in St. Paul Park, Minnesota, along with associated terminals, pipelines, and inventory as well as 166 SuperAmerica convenience stores to Northern Tier Energy for $900 million.^[20]

Post-corporate spin-off from Marathon Oil

On June 30, 2011, Marathon Oil distributed all of its shares in the company to its shareholders via a corporate spin-off.^[11]

In June 2012, Wheeling, West Virginia-based Tri-State Petroleum signed a contract to switch 50 stations in Ohio, Pennsylvania, and West Virginia to the Marathon brand. Most of Tri-State's stations before the deal were ExxonMobil-branded stations, the majority Exxon as well as a few scattered Mobil stations in the immediate Wheeling area. Included in the deal were 18 Exxon stations in the Pittsburgh metropolitan area, significantly boosting Marathon's presence in the Pittsburgh market, where former parent company U.S. Steel is based. (Exxon would offset its Pittsburgh losses by taking over the retail contracts of several Shell stations in the area, leaving Shell with a significantly reduced presence, while the Mobil brand was withdrawn from the Northern Panhandle of West Virginia altogether.) Before the deal, Marathon had a much smaller presence in Western Pennsylvania, while having a somewhat larger presence in West Virginia and an almost ubiquitous presence in Southern Ohio.^[21]

In 2013, Marathon purchased numerous assets from BP including a 451,000 barrel per calendar day refinery in Texas City, Texas, four light product distribution terminals, and retail marketing contracts for 1,200 retail stations throughout the southeastern United States.^[22]

In 2014, Speedway LLC, a now-former subsidiary of the company, purchased the retail operations of Hess Corporation for $2.82 billion.^[23] The deal also introduced the Marathon brand name at stations for the first time in the Northeastern United States east of the Appalachian Mountains and north of Pennsylvania. Prior to the deal, Marathon's traditional marketing territory for decades had been the Midwestern and Southeastern United States, never going further east than the Pittsburgh metropolitan area.

Refinery fire

In 2016, a fire at the Galveston Bay refinery in Texas City, Texas, injured three contract workers, resulting in a lawsuit seeking $1 million in damages.^[24] Multiple lawsuits were filed resulting in Marathon paying $86 million to settle.^[25]

2018 acquisition of Andeavor, sale of Speedway LLC

On April 30, 2018, Marathon agreed to buy Andeavor, an independent refinery and oil company based in the Western United States, for $23 billion.^[26] Marathon will acquire all of Andeavor's outstanding shares.^[27][28] On October 1, 2018, the merger was completed. This merger brings the SuperAmerica convenience stores back to Speedway.^[29] On October 31, 2019, Marathon announced plans to spin off their Speedway convenience stores. Gary Heminger will also retire from his role as Marathon Chairman and CEO.^[30][31] The deal also had the effect of introducing the Marathon brand name at stations in the Western United States for the first time and making Marathon a national brand name for the first time, as well as giving Marathon ownership of the ARCO brand.

On August 2, 2020, Marathon announced that Seven & i Holdings Co., Ltd. would be acquiring Speedway for $21 billion. The deal was anticipated to close in early 2021 pending regulatory approval.^{[32][33][34][35][36]} The deal closed on May 14, 2021.^[13]