The integrated oil company now known as Sunoco began as The Peoples Natural Gas Company in Pittsburgh, Pennsylvania. In 1886, its partners—Joseph Newton Pew and Edward O. Emerson—decided to expand their gas business with a stake in the new oil discoveries in Ohio and Pennsylvania. Four years later, the growing enterprise became the Sun Oil Company of Ohio. Sun Oil diversified quickly, active in production and distribution of oil as well as processing and marketing refined products. By 1901, the company was incorporated in New Jersey as Sun Company and turned its interest to the new Spindletop field in Texas.
With a growing portfolio of oil fields and refineries in hand, Sun opened its first service station in Ardmore, Pennsylvania in 1920. The name changed back to Sun Oil Company in 1922 and, 1925, Sun became a publicly traded company on the New York Stock Exchange. Following World War II, Sun expanded internationally. Its first Canadian refinery was built in 1953 in Sarnia, Ontario, home to a burgeoning new petrochemical industry. Sun established a facility at Venezuela's Lake Maracaibo in 1957, which produced over a billion barrels before the operation was nationalized in 1975.
Sun is perhaps best known to consumers for its "custom blending" pumps, an innovation that, in 1956, allowed customers of Sunoco service stations to choose from several octane grades through a single pump. In 1967, Sun established its Great Canadian Oil Sands Limited facility in northern Alberta, Canada, to help unlock the estimated 300 billion barrels of recoverable oil in the Athabasca oil sands.
With increased diversification, Sun Oil Company was renamed Sun Company in 1976. In 1980, Sun acquired the U.S. oil and gas properties of Texas Pacific Oil Company, Inc., a subsidiary of The Seagram Company, Ltd., for $2.3 billion -- the second largest acquisition in the U.S. history to that date.
Through the 1980s, Sun developed oil interests in the North Sea and offshore China and expanded its holdings in both oil and coal with additional U.S. business acquisitions. In 1983, consumers saw the arrival of Sunoco ULTRA, the market's highest octane unleaded gasoline. Then in 1988, Sun's undertook a major restructuring to segregate its domestic oil and gas exploration and production business and the focus the company on its refining and marketing business. This led to the acquisition of Atlantic Petroleum Corporation, including its Philadelphia refinery which was later merged with the adjacent Chevron refinery.
By the 1990s, Sun had departed the international exploration business and was fully dedicated to its branded products and services. The "Sunoco" became central to the company in 1998 when Sun Company, Inc. became Sunoco, Inc.