Archibald Smellie Brown was born in Glasgow, Scotland in 1892.
He was working as a Scottish textile agent when he emigrated to Canada as a young man and moved to Toronto. When war broke out he enlisted with the 58th Battalion of the Canadian Army. He likely fought during the Battle of Mount Sorrel in June 1916, and in the Battle of the Somme the following October.
The 58th Battalion served at Vimy Ridge in April 1917, and also fought during the Battle of Passchendaele, where he was wounded on October 26th, 1917. He was sent back to England to recover and then sent back to France for the remainder of the war. He was in Ypres when the Armistice was declared. While in a field hospital in France, he met his future wife, Minnie Robbins.