Roscoe is a borough in Washington County, Pennsylvania, United States. The population was 716 at the 2020 census. Roscoe became the home for many eastern European immigrants who came to the area to work in nearby coal mines. Slovaks, Poles, Serbs, Croatians, Italians, Hungarians, and Rusyns are all represented in census records of the area from 1…Roscoe is a borough in Washington County, Pennsylvania, United States. The population was 716 at the 2020 census. Roscoe became the home for many eastern European immigrants who came to the area to work in nearby coal mines. Slovaks, Poles, Serbs, Croatians, Italians, Hungarians, and Rusyns are all represented in census records of the area from 1880 onward.