But a portion remained with Peter Jr.'s heirs, who added to it to become major Pennsylvania producers of iron in the mid-19th century, operating out of Mount Hope Estate.
The Grubb brothers were major contributors to the Revolutionary War effort, their Cornwall Ironworks supplied cannon, ammunition, shot and saltpans (used to make salt from seawater) to the Colonial forces.
Their ongoing feuds and legal entanglements led to the fragmentation of the ironwork's ownership and its eventual loss by the Grubb family into the hands of Robert Coleman, who used it to build his fortune.
Peter, who had been running the forges, became fearful and reacted by purchasing land at Mount Hope to build his own furnace in competition with his brother, going heavily into debt.
The feud intensified and Peter III became concerned for the business and sold his interest to Robert Coleman, a friend who had worked for the brothers and was by then also an ironmaster.
Before the brothers took over the ironworks in 1765, Peter had moved to the mansion built by his father and was learning the iron making business.
On two occasions he was brought before Council to answer for statements he made while drinking; he was acquitted both times, as he had just "behaved in his usual mad way."
Certainly Peter's drinking problem contributed to his suicide in 1786; he took his own life at the Hopewell Forges and was buried there by his brother-in-law Jasper Yeates.
Hannah is believed to have then moved with her daughter to Curtis Grubb's household to help care for his two young children, whose mother had also died, probably in childbirth.