The first country to refine oil was the United States. The earliest commercial oil refinery was established by Samuel Kier in Pittsburgh, Pennsylvania, in the early 1850s. Kier began refining crude oil to produce kerosene for lamps, which marked the beginning of the modern petroleum refining industry.
The first country to start refining oil was the Russian Empire. In 1745, the first oil fields were discovered in what is now Ukraine. However, large-scale oil refining began in 1823, when the first oil refinery was built in the city of Baku (the capital of Azerbaijan). Baku became the center of the oil industry of the Russian Empire and one of the largest oil-producing regions of the world in the 19th century.