In the early twentieth century, down the Ohio River from Pittsburgh, the Jones & Laughlin Steel Company built one of the largest mills in the world and a town to go with it. Aliquippa was a beacon and a melting pot, pulling in thousands of families from Europe and the Jim Crow south. The J&L mill, though dirty and dangerous, offered a chance at a better life. It produced the steel that built American cities and won World War II and even became something...