South New Castle, PA

South New Castle sits south of New Castle in Lawrence County, in a residential pocket that spent 124 years as its own borough. The borough was created in 1901 from Shenango Township, and the J. P. Byers School opened to serve children of the new municipality. The old borough building and Byers School give the place a civic outline, while Big Run marks the low ground and Shenango Township surrounds the community.

The chapter changed January 1, 2026, when South New Castle merged into Shenango Township after voters in both municipalities approved the move. The name still works as a local place-name, while code enforcement and other municipal business now sit with the township. The surviving story is one of a small borough that kept its own address, school, fire department, and meeting places for generations before joining the township around it. South New Castle's present identity is both neighborhood and former municipality, with the old borough buildings carrying the memory of the separate government.