Hello - Graeme Park has a Fergusson in our history. Henry Hugh Fergusson married Elizabeth Graeme in 1772. He was actually 11 years younger than her and not considered to be a "good match" for this wealthy daughter of a doctor and prominent member of Philadelphia society. They met when he was just over from Scotland and was invited to one of Elizabeth's literary salons by a mutual friend. Because of her family's disapproval of the match, she ended up marrying him in secret and on the day she planned to tell her father of the marriage, he died while walking in the garden, so she never did reveal her secret. During the American Revolution, Henry served the British and was thus branded a traitor by the new American government. Because of this most of Elizabeth's worldly possessions were sold at auction and Graeme Park was also slated for sale, although she did finally get it restored to her.
We don't know a lot about Henry, he was said to be a relative of the philosopher Adam Fergusson, but we don't know how. After the Revolution he returned to England and ended up in Flanders with the army. It is not known what became of him after that. He had no children with Elizabeth but was alleged to have an illegitimate daughter with a friend's maid.