Leonard G. McCann was born on February 3, 1927 in Shanghai where his family had lived since the 1860s. He spent his childhood years there, attending St. Giles British School.

During WWII, he and his mother, Barbara McCann, were interned in a Japanese prisoner-of-war camp at Santo Tomas University in the Philippines from 1942 to 1945. While interned, the McCanns participated in the functioning of the camp’s internal administration, Barbara as a Room Monitor and Leonard working in the gardens and hospital. Following liberation, internees were evacuated from the camp beginning on February 11, 1945. The McCanns were taken by ship to San Francisco, California, but quickly relocated to Canada to avoid the US Military draft, to which Leonard would have been susceptible.

After the war, the McCanns came to Victoria, BC based on a sponsorship from Leonard’s aunt and uncle. Here, he worked various jobs including ship fitter's apprentice, drapery salesman and Land Registry office clerk before landing work at the new CBC television operation in Vancouver. After briefly working at CBC in Toronto, he returned to the West Coast to work for BCTV. A training course for museum workers and archivists led him to work for the Royal Canadian Engineers Museum in Chilliwack. In 1968, he joined the Vancouver Maritime Museum, where he worked as curator until his retirement in 1993.