In the 18th and 19th centuries, iron furnaces were a powerful contribution to the American economy and the transition from a pioneer lifestyle into a more modern one. If you have ever passed by an old iron furnace and wondered how old it was, how it worked, and how it shaped history—keep reading!

In the Beginning

The first well-known bloomery style iron furnace was constructed during the early 1700’s in south-east Pennsylvania, Lebanon County, Cornwall. Word of the booming Pennsylvanian iron industry trickled through the mountains and found its way to the Monongahela River Valley, Appalachian Mountains, Shenandoah Valley, and Potomac River area. By the 1800’s there were iron furnaces being built as far south as Georgia. George Washington even visited the notable bloomery of Harpers Ferry, West Virginia, and decided it was promising enough to build a federal arsenal close by. Wheeling, West Virginia, was even nicknamed “The Nail City” for its high production of nails made from iron ore. Much of the iron produced in these mountain states provided material to be forged for use in the Revolutionary War, the War of 1812, the Mexican War, and the Civil War.

The West Virginia Geological and Economic Survey mentions that iron furnaces were used to create cooking utensils, cannonballs, iron grates, gates, fences, nails, and solid iron bars that were used as currency.

How do iron furnaces operate?

Iron furnaces need three things to run successfully: iron ore, plenty of timber, and a nearby water source. The water source, such as a river or creek, would need to have enough power to turn a large wheel to provide air for the furnace fire. These three elements made the Appalachian Mountains a perfect place for furnaces thanks to the access to all three resources they provided.

Although it did not take very many people to run the furnace itself, other laborers were employed for mining, iron hauling, carpentry, and animal care. Workers were also hired for tree felling and resource preparation, such as making charcoal.

Prospectors would select a site that was rich in limestone and iron; the iron would be mined and hauled by oxen to both the furnace and a nearby storage area. Ironworkers would feed iron and charcoal into the top of the furnace, a stone or clay structure that was typically 30 square feet at the bottom and as high as 40 feet tall. Limestone reduced the impurities of the finished product and was only added when available. Charcoal makers, known as colliers, were in charge of making the charcoal for the iron smelting process. A bellows that was connected to a river or creek-powered wheel would supply air for the fire to burn at temperatures up to 3000 degrees. The byproduct of heating iron created a material called slag, with silicon compounds that give it a glass-like sheen. Slag can still be found along riverbanks close to a furnace.

Creating charcoal was a laborious process on its own. Colliers manned up to 9 hearths at a time holding up to 30 cords of wood at once. Temporary structures were built to protect these burning pits from rain and to keep in the heat. At night, these charcoal pits combined with the glow of the furnace could light up much of the surrounding area. The nearby furnace-sustained town would see a flickering orange glow radiating from the forest.

Iron furnace communities

Most iron furnaces continuously ran for 7 days a week, even at night. Just like the coal mining communities, these furnaces provided the base means for a societal structure. Entire towns were centered around the work that iron furnaces provided. The United States Department of Agriculture, Forest Service branch website explains that, “These communities consisted of the mansion of the iron master, cottages for the laborers, tool and storage sheds, shops for carpenters and blacksmiths, a store, stables, for mules and oxen, schools for employees’ children, and the furnace.”

What failed the Appalachian iron industry?

Transportation was simply not efficient enough because railroads only came so close to the production site. This left workers to haul the iron by oxen, which was slow, dangerous, and expensive.

Traveling to Appalachia this spring?

Iron furnaces are rich in history and are an absolute wonder to see in person. Next time you are traveling through the mountains or are taking a scenic drive along the Blue Ridge Parkway, consider visiting these historical Appalachian attractions.

Add these stops along the way!

  • Roaring Run Furnace, located in the Jefferson National Forest in Botetourt County, Virginia.
  • Salisbury Furnace, also in Botetourt County, Virginia.
  • Washington Iron Furnace at Rocky Mount, Franklin County, Virginia.
  • Bloomery Furnace in Bloomery, West Virginia.
  • Henry Clay Furnace at Coopers Rock near Morgantown, West Virginia.
  • Virginia Furnace, adjacent to Route 26, near Albright, West Virginia.
  • Cumberland Gap Furnace at The Cumberland Gap National Historic Park in Tennessee.