John S. Hammond III, of Lincoln, MA, died unexpectedly at his home of natural causes on September 16, 2018. John was born April 30, 1937, in Detroit, MI, to Alice Hirschman Hammond and John S. Hammond II. He attended Grosse Pointe High School in a Detroit suburb before going to Harvard College. While pursuing an undergraduate degree in physics, John was an all-American swimmer and was later inducted into the Harvard Varsity Club Hall of Fame. After college, he did computer memory research near Los Angeles at NCR and simultaneously pursued part-time a Masters in Engineering at UCLA. In Los Angeles he met his future wife, Nancy Campbell, of Fremont, NE. They were married June 1964 just before they moved to the Boston area, where John entered the Doctoral Program at the Harvard Business School. In 1968 he joined the Harvard Business School faculty, and Nancy and John bought a fixer-upper farmhouse on what grew to be eight acres in Lincoln, MA, where they raised their two daughters and lived for 50 years. At Harvard John taught Decision Analysis, Computer Modelling and then pioneered the teaching of Negotiation, now widely taught in all venues. John left HBS in 1976 for a 40-year career as an independent management consultant specializing in Negotiation and in Strategic Planning. He advised, coached and taught senior management at over 100 organizations, from Fortune 500 firms to the smaller and privately-owned. He also taught strategy at MIT's Sloan School and co-authored the capstone marketing text: Strategic Market Planning and the award-winning Smart Choices: A Practical Guide to Making Better Decisions, which was translated into 15 languages. More recently he was deeply involved in environmental causes, especially climate change, and served as a trustee and Massachusetts Advisory Board member for the Conservation Law Foundation and as a member of the Mass Audubon Advisory Council. He enjoyed traveling, vegetable gardening, aviation, and historical aerial photography. He leaves his wife of 54 years, Nancy, and two daughters, Sarah Hammond of San Francisco, CA, and her husband Tim Carlstedt, and Kate Hammond of Morrison, CO, and her husband Geoff Brown; grandchildren Camden and Tate Carlstedt, and Avery and Miles Hammond; and a sister, Barbara Sepenuk of Portland, OR. His sister, Betsey of Lynn Harbor, FL, predeceased him. The family kindly requests no flowers. John would be delighted if you took action for the environment. A celebration of John will take place at 2 pm on Sunday, October 14, 2018 at the Pierce House at 17 Weston Road in Lincoln. Feel free to come in gardening clothes or any other comfortable attire to enjoy ice cream with us and hear a few John stories. Arrangements are under the care of Dee Funeral Home & Cremation Service of Concord.