The Anderson-Prichard Oil Company was originally founded in the late 1910s in Oklahoma, and served a major role in the oil and gas industry for over the next fifty years. After successful early petroleum oil discoveries in Oklahoma, Louisiana, and Texas, the corporation expanded quickly, building a large refinery in Cyril, Oklahoma. The company later went public in the 1940s and acquired Kanotex Refining in 1953. By 1955, the corporation was listed as a Fortune 500 company. In 1960, the company’s assets were broken up and sold off for over $123 million. The assets were bought by a few different groups, including Occidental and Seagram corporations. One portion which included included the Anderson-Prichard marketing and distribution units was incorporated in Delaware as a completely new organization, named “APCO Oil Corporation”. The initial, family-owned company ceased existence in 1960, and APCO Oil was a completely different company.

Marathon Oil Corporation, usually simply referred to as Marathon Oil, is an American petroleum and natural gas exploration and production company headquartered in the Marathon Oil Tower in Houston, Texas. Marathon Oil is incorporated in Ohio. The company predecessors were The Ohio Oil Company, and U.S. Steel.

Occidental Petroleum Corporation (often abbreviated Oxy in reference to its ticker symbol) is an American company engaged in hydrocarbon exploration in the United States, the Middle East, and Colombia as well as petrochemical manufacturing in the United States, Canada, and Chile. It is organized in Delaware and headquartered in Houston. The company is ranked 722nd on the Forbes Global 2000 and 220th on the Fortune 500. In 2018, the company was the 9th largest petroleum producer in Texas.