Why did people begin to pump oil from the ground?

Second Answer;;People began to pump oil from the ground because, chemists invented a way to convert unprocessed oil, or crude oil into a fuel called kerosene. Kerosene could be used for cooking, heating and lighting. Then there was a sudden demand for oil. It further expanded when Edwin L. Drake proved that it was possible to pump crude oil from the ground. Suddenly wildcatters or oil prospectors drilled for oil in Ohio, Pennsylvania, and West Virginia.

In order to obtain raw materials for industry: fuel, lubricants, etc.