Diahn Williams McGrath had a successful television and film career in the 1960s and 1970s, before she became a NYC-based lawyer. Her husband is a retired partner of the NYC law firm Simpson, Thatcher & Bartlett.
They purchased Eastfair Castle in 1971 after the former owner and their close friend, Sherman Mills Fairchild, had died. Fairchild was an inventor, entrepreneur who founded over 70 companies, and IBM heir.
Eastfair Castle was built around 1930.