Speedway is a wholly owned subsidiary of Marathon Petroleum.
Speedway began as Speedway 79, a Michigan based gas station chain.
In 1959, the company was purchased by the Ohio Oil Company (now Marathon) and all stations were converted to Marathon brand.
Speedway and SuperAmerica were combined in 1998 when Marathon and Ashland merged.
In 2011, Marathon sold SuperAmerica. The two chains are now unrelated.
In 2012, the company acquired GasAmerica and all 88 of their stations in Ohio and Indiana.
Today, there are nearly 3,000 Speedway gas stations in Ohio, Michigan, Indiana, Illinois, Kentucky, Pennsylvania, Tennessee, West Virginia, and Wisconsin, making it the second largest chain of gas stations/convenience stores in the US.