After completing his B.A. in History in 1943, he went on to an M.A., with a thesis on "Sir John A. McDonald and Kingston". He moved to Winnipeg to teach at the University of Manitoba from 1945 to 1966. During these years, he was active with the Faculty Association, the Institute of International Affairs, the Winnipeg Little Theatre, and the Royal Winnipeg Ballet. He served as Dean of Men's Residence from 1950 to 1953. During the Winnipeg years, he took time out to study at the University of Chicago, and completed a Ph.D. dissertation on relations between France and Canada in the Napoleonic era.
Dr. Stewart returned to Queen's in 1966 to become its first Dean of Student Affairs, and guide the University through the turbulent late sixties. In 1973 he returned to full-time teaching in the Department of History.
After retirement in 1980, Webster continued his involvement with Queen's. For his contributions he received the Herb Hamilton Award for exceptional service to the Queen's Alumni Association. In 1996 the Queen's University Council presented him with the Distinguished Service Award.
Throughout his entire life Dr. Webster vacationed as much as possible at Silver Islet on the north shore of Lake Superior and considered it the most beautiful place on Earth. Dr. Webster passed away in Kingston in March 2007.