Bowser was born in Whitchurch township, Ontario, Canada, present-day Aurora in 1892. He left home at age 11, returning to the Toronto area at age 15, then working on several construction jobs including a tunnel to connect Eaton's store with the Annex, the Royal Ontario Museum, and the Bank of Toronto building. Hired by an American firm, he was sent to Tokyo. Later, he was responsible for demolition of old Madison Square Gardens, and the Waldorf-Astoria Hotel.