Marathon Petroleum Corporation's origins trace to 1887, when several small oil companies banded together to form The Ohio Oil Company in Lima, Ohio. The American petroleum industry was in its infancy, and Lima was at the center of one of the nation's first major oil discoveries. In 1889, just two years after its founding, The Ohio Oil Company was purchased by John D. Rockefeller's Standard Oil Trust, the dominant force in American industry. Corporate headquarters were moved to Findlay, Ohio, in 1905, and the company operated as a subsidiary of Standard Oil for more than two decades. The pivotal moment came in 1911, when the U.S. Supreme Court broke up the Standard Oil monopoly under the Sherman Antitrust Act. The Ohio Oil Company was once again independent, free to pursue its own strategy but also stripped of the protective umbrella of the world's largest corporation. The interwar years were a period of expansion and transformation. In 1906, the company constructed its first pipeline, running from Martinsville, Illinois, to Preble, Indiana. In 1915, Ohio Oil created Illinois Pipe Line Company and immediately spun it off, demonstrating an early understanding of the value of focused operations. In 1924, the company purchased Lincoln Oil Refining Company, which included the Robinson refinery in Illinois and 17 Linco brand service stations. But the most transformative acquisition came in 1930, when Ohio Oil purchased Transcontinental Oil Company. The deal brought oil and natural gas wells, three refineries, bulk storage plants, and filling stations. Most importantly, it included the Marathon product name, the Pheidippides Greek runner trademark, and the 'Best in the Long Run' slogan. In that same year, Ohio Oil Company's stock was publicly traded on the New York Stock Exchange for the first time. The Marathon brand, with its evocation of endurance and long-distance performance, would become one of the most recognizable names in American petroleum retailing. The 1940s and 1950s brought technological and marketing innovation. In 1945, thermal cracking gave way to catalytic 'cat' cracking, increasing refinery yield. Ohio Oil began a highly successful campaign extolling the virtues of Marathon 'Cat' gasoline. In 1946, Marathon service stations took on a new look, offering tires, batteries, and accessories, and auto maintenance in service bays. 'Best in the Long Run' became a familiar sight to motorists in the Midwest. In 1953, The Ohio Oil Company was the first to introduce the metal credit plate, the precursor to the modern credit card, to build customer loyalty. In 1959, the company purchased Aurora Gasoline Company, acquiring 680 service stations featuring the Speedway 79 Stratofuel brand. It also purchased the Detroit refinery from philanthropist Max Fisher. In 1960, Marathon Pipe Line Company was created as a subsidiary, and in 1962 the company officially changed its name to Marathon Oil Company. The 1970s and 1980s brought both opportunity and crisis. The 1973 oil embargo and subsequent price spikes created windfall profits for oil producers but also exposed the vulnerability of US energy dependence. Marathon Oil expanded internationally, with production in Libya and Nigeria and refining and marketing in Europe. But the 1986 oil price collapse, which saw prices fall below $10 per barrel, devastated the industry. In 1982, Marathon Oil was acquired by U.S. Steel Corporation (later USX Corporation) in a $6.5 billion deal, becoming part of a diversified industrial conglomerate. The marriage of steel and oil was never comfortable, and in 2001 USX Corporation split into two independent companies: United States Steel Corporation and Marathon Oil Corporation. The newly independent Marathon Oil Corporation focused on exploration and production, with headquarters in Houston, Texas. But the company's downstream assets—refineries, pipelines, marketing, and retail—were increasingly seen as a strategic misfit within an upstream-focused company. On January 13, 2011, Marathon Oil announced that its board had authorized a spin-off of the downstream business into a separate, independent company. On June 30, 2011, Marathon Petroleum Corporation was spun off from Marathon Oil, with Marathon Oil stockholders receiving one share of MPC common stock for every two shares of Marathon Oil common stock they owned. The newly independent Marathon Petroleum Corporation, headquartered in Findlay, Ohio, inherited a refining and marketing business with roots stretching back to 1887. The spin-off was transformative. Freed from the capital allocation priorities of an upstream-focused parent, Marathon Petroleum pursued aggressive growth in downstream assets. In 2012, the company acquired BP's Texas City refinery and related assets, adding significant Gulf Coast capacity. In 2014, it acquired Hess Corporation's retail operations, expanding its East Coast marketing footprint. But the most consequential transaction in the company's modern history came on April 30, 2018, when Marathon Petroleum and Andeavor announced a definitive merger agreement. Andeavor, formerly Tesoro Corporation, was a highly integrated refining, marketing, and logistics company operating primarily in the Western and Mid-Continent United States, with 10 refineries, more than 3,300 retail stations under brands including ARCO, and a midstream business conducted through Andeavor Logistics. The acquisition, completed on October 1, 2018, was valued at $23.3 billion in equity and $35.6 billion in enterprise value. It created the largest independent refiner in the United States, with 16 refineries, more than 3.0 million barrels per day of capacity, and a coast-to-coast retail and marketing platform. The transaction was immediately accretive to earnings and cash flow per share, and management expected up to $1.4 billion in gross run-rate synergies by the end of 2021. The integration was complex—combining two large organizations with different cultures, systems, and geographic footprints—but the strategic rationale was compelling. The Andeavor acquisition gave Marathon Petroleum access to Western US markets, including California, where refining capacity is constrained by environmental regulations and geographic isolation from Gulf Coast supply creates structurally higher margins. It also added the ARCO brand, a powerful retail franchise in the Western United States, and expanded the company's midstream footprint in the Permian Basin. In 2020, Marathon Petroleum made a counterintuitive but strategically sound decision: it sold its Speedway retail convenience store business to 7-Eleven for $21 billion. The sale, completed in August 2020, included approximately 3,900 stores and removed a stable but capital-intensive business that was increasingly peripheral to the company's core refining and midstream strategy. The proceeds were used to reduce debt, strengthen the balance sheet, and return capital to shareholders. In 2024, Maryann T. Mannen was appointed President and Chief Executive Officer, succeeding Gary R. Heminger. Mannen, who had served as President since 2023 and previously held roles including Executive Vice President and Chief Financial Officer, brought deep financial and operational expertise to the role. Under her leadership, the company established a Renewable Diesel segment as a separate reportable business, reached full production at the Martinez Renewables facility, and delivered peer-leading capital returns of $10.2 billion in 2024 and $4.5 billion in 2025. The company that began as a collection of small oil companies in Lima, Ohio, in 1887 has become a $74.6 billion integrated downstream energy giant. But the entrepreneurial spirit of its founders—banding together to compete against larger rivals, adapting to technological change, and enduring through every industry cycle—remains embedded in its culture.