Dr. Graeme was the husband of Ann Diggs who was the stepdaughter of Sir William Keith. Graeme had arrived with Keith from England in 1717 and married Ann in 1719. During his years in Pennsylvania Graeme attained a significant social status in Philadelphia. He served as the Port Physician, was a consulting physician at the Pennsylvania Hospital, was appointed as a Naval Officer by Governor Keith in 1719, as a Register General and Master of Chancery in 1724. Graeme also served on the Provincial Council and the Supreme Court of Pennsylvania. Governor Keith had left Pennsylvania in 1728 and left trusteeship of his properties to his wife Lady Anne Keith and family. Dr. Thomas Graeme was one of the trustees. The estate was sold in 1738 to Joseph Turner, who then sold Fountain Low to Dr. Graeme in 1739. Graeme originally used the newly named Graeme Park as a summer residence and kept his primary residence in Carpenter's Mansion on Society Hill in Philadelphia.