

John was born on June 3, 1936, in Cincinnati, Ohio, to his parents John and Edna Denniston. He attended Walnut Hills High School and received a Bachelor of Engineering Physics from Cornell University. Upon graduation, he was a rocket scientist at Rocketdyne in Pasadena, California. Realizing an opportunity to merge his scientific aptitude with the practice of law, he enrolled at Harvard Law School. After receiving his law degree, he was a Fulbright Scholar at the University of Sydney, Australia.
John spent his entire legal career with Covington & Burling, LLP in Washington, D.C., specializing in government contracts. He primarily represented defense, transportation, and energy companies.
He was devoted to his family, always putting them first. He is survived by his loving wife of thirty-four years, Susan Russell Denniston, his three adoring children, Derek, Lavinia, and Miles, his step-sister Denise Fisher, and his step-daughter Caroline Pulsifer. He absolutely doted upon his five grandchildren, Chloe and Zack Denniston, and Katherine, Hale, and Taylor Pulsifer.
John loved outdoor sports, especially running, hiking, skiing, biking, and paddle sports. He also had a passion for trekking that led him to the Himalayas, including the regions of Sikkim, Zanskar, and Bhutan, the Rwenzori range in Uganda, Mount Kilimanjaro in Tanzania, and the Andes in Peru. The highlight of his trekking adventures was participating in the reenactment of Sir Ernest Shackleton’s traverse of South Georgia Island off the coast of Antarctica.
He was an enthusiastic traveler, and he particularly enjoyed exploring the world with his wife, Susan. They rode elephants in search of tigers in India, looked for the ‘Big Five’ on safaris in Africa, cruised the South Pacific, sailed in the Galapagos, hiked in Patagonia for the dawn of the millennium, biked through the Loire Valley in France, amongst many exotic locations across the seven continents, often with his family happily in tow. Their last trip was to see the polar bears in Churchill, Manitoba.
John also thoroughly enjoyed all the activities and wonderful friendships forged over the years at The Metropolitan Club, Chevy Chase Club, and Monterey Country Club.
One of John’s earliest and greatest loves was reading, yet his ability to read was cut short during the last years of his life by severe glaucoma. In lieu of flowers, please consider a gift to The Glaucoma Foundation, 80 Maiden Lane, Suite 700, New York, New York 10038 or glaucomafoundation.org.
John was dearly loved, and will forever be missed. A celebration of life will be scheduled at a later date.
DONATIONS
The Glaucoma Foundation80 Maiden Lane, Suite 700 , New York, New York 10038
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