The Ulster Iron Works Company was an iron foundry and manufactory situated on the Hudson River near the iron deposits of Ulster County, 100 miles north of New York City. The company was a financially successful and fairly long-lived operation having been established before the mid-1820's, and continuing in operation through at least the end of the Civil War. The works was involved in most phases of iron production, from smelting through the manufacture of wrought iron and cast iron products for industrial and military use.
Among the factors that contributed to the success of the Ulster Iron Works was the ability of the owners of the corporation to arrange for government contracts, especially contracts with the Navy, for providing iron products for use in rockets, ships, and other materials. In civilian applications, Ulster was an important purveyor of iron products for railroads and shipping. Also contributing to the success of the works was the unusual diligence of the owners in importing foreign technologies for use at Ulster, and in soliciting the emigration of highly skilled workmen from Welsh and English foundries to fill their employment demands, particularly during the 1830s when skilled labor was at a premium. The owners appear to have been quite successful at using high wages as a lure to skilled workers during such periods, but they were equally ruthless at cutting wages when labor was abundant. At the same time, there is some evidence for the persistence of a more patriarchal attitude on the part of the foundry owners toward their employees, and the on-site manager, John Simmons, at least maintained a personalized, face-to-face relationship with his workers.