Nail manufacturer Abner Davis's life shows how Philadelphia's economy shifted from handicraft to industry in the early days of the 19th century. Colonial blacksmiths forged nails one at a time, but by the 1790s, machines had been developed that could cut many nails from one long iron bar and, later, shape the heads as well. Davis was one of the first to adopt this new technology: in addition to running his own shop, he was in 1795 appointed as an assistant keeper at the Walnut Street Prison to "help direct the work… of the Men in the Yard, Smith Shop, & Nail Factory," which he had set up.