<P> Petroleum became a major industry following the oil discovery at Oil Creek Pennsylvania in 1859 . For much of the 19th and 20th centuries , the US was the largest oil producing country in the world . As of October 2015 , the US was the world 's third - largest producer of crude oil . </P>
<P> Petroleum became a major industry following the oil discovery at Oil Creek Pennsylvania in 1859 . For much of the 19th and 20th centuries , the US was the largest oil producing country in the world . As of October 2015 , the US was the world 's third - largest producer of crude oil . </P>
when was oil first discovered in the us
when was oil first discovered in the us
1859
1859