The brothers operated the Cornwall Ironworks, making significant contributions to the American Revolutionary War effort, and Curtis served several terms in the Pennsylvania Provincial Assembly.
He was also one of the largest enslavers in Pennsylvania at the time of independence, registering twenty-five people as his property in 1780 in accordance with state gradual abolition law.
[1] The brothers inherited the ironworks from their father in 1754, with Curtis (the oldest) receiving a two-thirds interest and Peter one-third.
But a portion, including rights to access the ore, 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 brothers were major contributors to the Revolutionary War effort, their 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.
Curtis conveyed to his son an interest in the ironworks, which unfortunately required a legal subdivision of the assets that had previously been shared informally.
Peter, who had been running the forges, became fearful and reacted by purchasing land at a place he called 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.
With his previous acquisitions Robert Coleman became the owner of most of the former Grubb holdings, which he added to his own and expanded to become Pennsylvania's first millionaire.
But Curtis did return and eventually wanted to rectify the situation and requested the Provincial Assembly to dissolve the marriage and allow him to remarry.
Peter Jr. didn't want to marry again and it appears Hannah moved to Curtis' household to care for his infant children, along with her own.
She probably remained in Curtis' household until he decided to marry Ann, at which time she and their son Jehu would have been forced to move out.
The theory is strongly supported by the fact that Hannah, not his third wife Ann, was buried near Curtis at Tabor Reformed Church.