1887: The Ohio Oil Company is founded (corporate ancestor of later Marathon entities)

1905: Ohio Oil becomes part of Standard Oil’s successor structure, expanding refining and marketing reach

1920s–1930s: Expansion of upstream and downstream operations across the Midcontinent; broader product distribution

1962: “Marathon” becomes the corporate identity as Ohio Oil is renamed Marathon Oil Company, signaling unified national presence

1960s–1970s: Expansion of refining, transportation, and marketing; strengthened branded retail presence

1982: U.S. Steel acquires Marathon Oil, forming an integrated energy subsidiary with greater capital access

1990s: Modernization of refining assets and supply logistics, preparing for later downstream separation

2002: Marathon Oil becomes Marathon Oil Corporation (MRO) after U.S. Steel rebranding and refocus, emphasizing energy as core business

2000s: Refining and marketing upgrades; focus on efficiency, environmental compliance, and supply-chain integration

Late 2000s: Preparation to separate upstream (E&P) from downstream to enable focused strategies

2011: Marathon Petroleum Corporation (MPC) is spun off from Marathon Oil Corporation, becoming a standalone downstream company

2011: MPC operates as a major independent U.S. refiner with Midwest/Gulf Coast footprint and branded marketing network

2013: Acquisition of BP’s Texas City refinery and related assets, increasing Gulf Coast capacity and export optionality

2013–2015: Refinery upgrades, crude flexibility projects, and distribution improvements for broader feedstock processing

2015: Formation of MPLX by combining logistics assets into an MLP structure, strengthening fee-based midstream earnings and funding growth

2016–2018: MPLX expands via projects and acquisitions, extending gathering, processing, and pipelines supporting refining and regional supply

2018: Acquisition of Andeavor transforms MPC into the largest U.S. refiner by capacity; expands West Coast footprint and retail/marketing reach

2018–2019: Integration and optimization across refining system, crude sourcing, and product distribution

2020–2021: Focus on reliability, cost reduction, and capital discipline amid volatile demand conditions

2021: Sale of Speedway retail business to 7‑Eleven, sharpening focus on refining and midstream while monetizing retail value

2022: MPLX acquires remaining interests in several MPC logistics entities, simplifying structure and increasing midstream integration and cash-flow stability

2023: Emphasis on utilization, margin capture, and logistics optimization; disciplined capital allocation and shareholder returns

2023–2025: Development of lower-carbon initiatives (renewable diesel interests/partnerships where applicable, emissions reduction, efficiency upgrades) while maintaining refining leadership

Present: MPC operates as a leading independent refiner with integrated midstream platform (via MPLX), centered on operational excellence, system optimization, and selective transition investments