Soon after, he responded to the outbreak of World War I by resigning his commission to join the Royal Montreal Regiment as a company sergeant-major.

[3] The citation for his DSO, awarded for his actions during Canada's Hundred Days, reads: For sound ability in handling his battalion and great gallantry in the attack on the Canal du Nord on 27th September, 1918.

The couple raised six children: Marjorie (1918–1988), Lyall (1920–1942), Helen (1922–2014), Ann (1928–1997), Isabel (1930–1997), and John (1930–1993).

[6] In that post, which he held until the war ended, he strove to ensure that all Allied prisoners of war received equal benefits, including one large Red Cross parcel per month containing the best food available (white-flour biscuits; butter instead of oleomargarine, etc.).

In 1944 he joined John Bracken's team as the Progressive Conservative candidate in Saint-Antoine—Westmount,[7] and lost to the Liberal incumbent Douglas Charles Abbott by just 60 votes in the 1945 federal election.