Duncan married Ellen Gipsy Grover, daughter of John Grover and Thora Beathe Svendsen, on 18 Feb 1943 in Portsmouth, England. (Ellen Gipsy Grover was born on 8 Jan 1921 in Montreal, Quebec, Canada, died on 3 May 2000 in Toronto, Ontario and was buried on 6 May 2000 in Toronto, Ontario.)
