New Castle, city, seat of Lawrence County, western Pennsylvania, at the junction of the Shenango River and Neshannock Creek; incorporated as a city 1869. Local manufactures include pottery and metal, rubber, plastic, glass, stone, leather, and chemical products. Settled in 1798, the community probably was named for New Castle, Delaware. Local availability of iron ore, coal, limestone, and clay spurred industrial growth in the 19th century. Population 33,621 (1980); 26,309 (2000).
