1948, retired to Hilton Head Island, South Carolina. They had acquired a beach-front home in 1966 and the family spent many happy years vacationing there before he and Esther became full-time residents of the Sea Pines development in 1980. In the mid-1980s he became a founding director of Sea Pines Associates and he’s credited with organizing the homeowners in Sea Pines to purchase the resort and save it from failing and going into bankruptcy.

Simpson remained active throughout the next 20+ years, traveling extensively with Esther and entertaining friends and family in Hilton Head. He was deeply involved in the First Presbyterian Church both in Pittsburgh and on Hilton Head. In addition to his affiliations with many educational institutions and professional organizations, Simpson served on the board of the National Council of Churches. He maintained close ties with Pittsburgh too, keeping memberships at various clubs there, such as the Duquesne Club, the University Club, Laurel Valley Country Club, Rolling Rock Club, and others. He also belonged to Farmington Country Club in Charlottesville, Virginia, and Bear Creek Golf Club on Hilton Head. He loved golf, bridge, snow skiing, hunting, deep-sea fishing, fine wines, good friends, and debating on a myriad of topics.

Never one to rest and relax, he authored two books and continued to consult on nuclear matters with a number of different colleagues. “My father was especially proud of his membership in the National Academy of Engineering,” said his daughter, Patricia Deely. “Even at 92, he dressed in a shirt and tie and always wore his NAE lapel pin on his jacket.”

Simpson’s wife, Esther Slattery Simpson, passed away on August 6, 2004. John is survived by his four children—John Simpson Jr., Carter Berkeley Simpson, Patricia Deely, and Barbara Wilkinson—and five grandchildren—Christina and Carter Berkeley Simpson Jr., Savannah Wilkinson, Sean and Emily Deely—and two step-grandchildren—Dan and Matt Deely.