In 1804, Eli Whitney constructed a forge. He used traprock quarried just 500 yards uphill from the site. The forge was the first and largest of the five buildings that Whitney Sr. constructed on the east side of the Mill River.
The dam to the north of the site was constructed later. In 1804, a stone channel brought water from a smaller dam under the forge to turn a waterwheel that powered the forge's bellows. The channel rejoined the Mill River at the bridge.
Barges brought mineral coal and charcoal up the river to fuel the forge's fires.
In the forge, blacksmiths shaped and welded musket barrels with hammers, anvils, and air pumped into carefully bedded coals. The building was purposefully dark to allow the artisans to judge the temperature of their welds as the steel turned red, then orange, then yellow, and finally, white. Eli Whitney, Jr. adopted more modern techniques for boring barrels in 1850. The building was used for other manufacturing until the early 1950s.
Industrial Archaeologists excavated the foundation in 1974. Yale students continued studies in the 1990s. The building's boundaries were re-excavated and marked by Mark Wesolowski's Eagle Scout project in 2008.
