America's First Iron Puddling Furnace

In eighteen seventeen, ironmaster Isaac Meason and a Welshman named Thomas Lewis built a puddling furnace and bar rolling mill at this site near Smock, introducing to America a process that changed everything about iron production. Puddling removed carbon from brittle pig iron in a single step, creating malleable wrought iron that was stronger, more workable, and far cheaper to produce than anything made before.

The technology came from Britain, where it had been developed decades earlier, and Meason and Lewis transplanted it to southwestern Pennsylvania at exactly the moment the region was becoming an industrial center. The downstream consequences were enormous. As the puddling trade grew in Pittsburgh, the workers who mastered the furnaces organized themselves into the Sons of Vulcan, an early iron and steel union and a forerunner of the United Steelworkers. A single furnace on Laurel Hill Road helped set that chain in motion.