![]() ![]() The movement away from charcoal in US iron smelting began in 1827, when a puddling furnace in Phoenixville, Pennsylvania started using anthracite coal. The Adirondack iron ore district of New York also supported iron smelters. The Cornwall Iron Furnace in Pennsylvania was established next to an iron deposit. ![]() New Jersey's principal iron ore district, at Dover, supported iron smelters beginning in 1710. Most US iron smelting before 1850 took place near iron deposits in eastern Pennsylvania, New York, and northern New Jersey. The proximity to larger ore deposits favored larger, more permanent iron smelters. Inland locations also allowed the furnaces to be closer to sources of limestone, which was used as a flux in iron smelting. In the late 1700s the iron furnaces moved away from the bog iron ore of the coastal swamps, to larger iron ore deposits further inland. Although the bog iron ores mined in colonial days were widespread, the deposits were also small, and quickly exhausted. ![]() Notable pre-19th-century iron furnaces in the US Nameīecause wood for charcoal was available throughout the eastern states, iron smelters were located close to iron ore. If one estimate of 30,000 tons of iron each year is accurate, then the newly formed United States was the world's third-largest iron producer, after Sweden and Russia. The law was widely ignored by colonial governments.īy 1776, up to 80 iron furnaces throughout the American colonies were producing about as much iron as Britain itself. Parliament compromised in the Iron Act of 1750, which eliminated the import duty on colonial pig iron, but barred the manufacture of steel or of iron plate in the colonies. In addition, the furnace needed to be close to a major market or close to water transport.īritish business interests were split on colonial iron: manufacturers appreciated the lower prices due to colonial imports, but the British iron and steel industry objected to the competition. Also required were forests for charcoal, iron ore, and limestone for flux. Iron furnaces were located along rivers to supply water power. While the Chesapeake Bay furnaces were established for export, iron furnaces were established in the 1700s throughout the American colonies for domestic consumption. By 1751, Virginia and Maryland were exporting 2,950 tons of pig iron to Britain each year at the time, British iron production was about 20,000 tons per year. That success prompted formation of more companies, which built numerous iron furnaces around Chesapeake Bay, supplied by bog iron ore, which was widespread. British investors started an iron furnace near Perryville, Maryland, which in 1718 started exporting iron back to Britain. Britain looked to the seemingly limitless forests of its American colonies to supply Britain with iron. By 1700, Britain was becoming increasingly dependent on iron imported from its sometimes-adversary Sweden. Iron manufacture before the 19th century required charcoal, and Britain's once-vast forests could no longer supply enough charcoal for the nation's increasing need for iron. Since the American industry peaked in the 1940s and 1950s, the US industry has shifted to small mini-mills and specialty mills, using iron and steel scrap as feedstock, rather than iron ore. In the 20th century, the US industry successively adopted the open hearth furnace, then the basic oxygen steelmaking process. In the 1800s, the US switched from charcoal to coal in ore smelting, adopted the Bessemer process, and saw the rise of very large integrated steel mills. The US iron and steel industry has paralleled the industry in other countries in technological developments. Graph of US iron and steel production, 1900–2014, data from USGS ![]()
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