Coatesville is the only city in Chester County, Pennsylvania, United States. The population was 13,100 at the 2010 census.
Coatesville grew up around the Lukens Steel Company. Lukens was bought by the Bethlehem Steel Corporation in 1997. In 2002, Bethlehem was bought by the then Ohio-based International Steel Group (ISG). Later, Mittal Steel bought ISG and then merged with Arcelor Steel to form the ArcelorMittal company.
The first known settlement in the area which would be known as Coatesville was a Native American village built along the Brandywine River. This settlement was a post for fur trading with the earliest American settlers. The Brandywine River features prominently in the history of Coatesville.