Hopewell Furnace National Historic Site

Visiting Hopewell Furnace National Historic Site | April 2023

We spent most of our free time in Pennsylvania hiking in Valley Forge, which was located just minutes from our hotel. But when Curtis would have full days off, we would venture out a little further and visit other historic sites. On our first Saturday in the area, we decided to drive 40 minutes West of King of Prussia to visit a smaller national historic site: Hopewell Furnace.

The park preserves the very intact, if reconstructed, remains of a single, pre-industrial, cold blast iron furnace. Hopewell Furnace was not particularly noteworthy for its time, and was but one of many furnaces to be built in the late 18th and 19th Centuries across the iron rich hills of Southeastern Pennsylvania and East Maryland. But it did have a remarkably long operating history of over 100 years (1771-1883) and the distinction of being preserved by the Department of the Interior in the 1930’s.

These cold blast furnaces operated on a fairly old (even for the 1700’s) recipe and made great use of the natural resources. The forest was used to generate charcoal for the fires, iron ore was mined from the hills, and the mountain streams were dammed and controlled to turn a water wheel, which in turn operated the bellows to provide the much needed oxygen to complete the chemical reaction. (The air in the bellows was not pre-heated, and supplied a continuous ‘blast’ of high pressure air, hence the term “Cold Blast”)

All the ingredients would be combined in a laborious process by shoveling tons of material into the top of the furnace, and then the furnace would be lit, and allowed to burn until the ore had been melted and refined. Once the iron master deemed the iron ready, the workers would tap the bottom of the furnace, and molten iron would flow out into pre-made sand cast molds. Towards the beginning of the furnaces operation, the craftsman made many intricate ironworks, especially cast iron stoves – of which there are many extant examples around the park. But as technology advanced and costs changed, the furnace began producing raw pig iron almost exclusively, and exporting that to workshops for final fabrication.

But technology moved on, and even with a brief resurgence in business during the Civil War, the furnace was unable to compete with the newer ‘coal fired’ steel mills and the industrial revolution ultimately closing for good in 1883 with the rest of the ‘small batch’ furnaces of SE Pennsylvania.

All of this we learned from the extremely knowledgeable and helpful ranger at the Visitor Center. After learning about the park, we set off in a light rain and walked through the village that would have supported the operations here, saw what appeared to be a future charcoal demonstration, the ruins of a failed coal fired furnace venture, and then the furnace itself – remarkably restored and complete with operational waterwheel and bellows. It even looked like they did smelting demonstrations during the summer, though the scale of iron batch would be significantly smaller.

We walked passed the village, generally following the ‘Horseshoe Trail’ towards a nearby reservoir/lake before returning to the car.

The NHS is nestled in French Creek State Park and some state forest land, and so we decided to venture up to a firetower, hoping to get some views despite the rain. Unfortunately, the tower was closed, and the summit quite treed in so we were unable to admire the scenery.

Then it began to rain much more heavily and we called it quits and made the drive back to our hotel, this time taking the scenic route. Which, let’s be honest, unless you’re driving through a city, most roads in Pennsylvania are exceptionally scenic!