Oil City is a city in Venango County, Pennsylvania known for its prominence in the initial exploration and development of the petroleum industry. It is located at a bend in the Allegheny River at the mouth of Oil Creek.
Initial settlement of Oil City was sporadic, and tied to the iron industry. After the first oil wells were drilled in 1861, it became central to the petroleum industry while hosting headquarters for the Pennzoil, Quaker State, and Wolf's Head motor oil companies.
Tourism plays a prominent role in the region by promoting oil heritage sites, nature trails, and Victorian architecture. The population was 10,557 at the 2010 census, and it is the principal city of the Oil City, PA Micropolitan Statistical Area.
In 1796, the state of Pennsylvania gave Cornplanter, chief of the Wolf Band of the Seneca nation, 1,500 acres (6.1 km2) of land along the west bank of the Allegheny River in Warren County, Pennsylvania, as well as a small tract on both sides of the mouth of Oil Creek, in compensation for his services during the American Revolutionary War. The first white settler in what became Oil City was an unknown individual who cleared and farmed about 400 acres (1.6 km2) on the west side of Oil Creek upstream from Cornplanter's land. Francis Halyday (or Holliday) purchased this land in 1803, and settled there with his family. The first white child known to be born in what became Oil City was James Halyday, born January 13, 1809.