In 1911, Harry married Janet mary Ellen Anderson.
During the First World War, Harry served with the 73rd Battery of the Canadian Field Artillery and his brother, Francis Xavier Amoss, who was awarded the Military Cross, also served with the Canadian forces in France.
After the war, Harry returned to Canada and to teaching. He died in February 1965.
A dedication Harry wrote in one of his books.
Here is a passage from Harry’s poem "Passchendaele 1917":
… war has stripped illusions Buddha-wise
Has tossed the tinsel on the winds astrew,
And with gaunt fingers rent the robes of pride
Till life in naked worth confronts the eyes
Harry's WW1 poetry collection was “Prayer of the Good Trouper and Other Poems” (Ryerson, Toronto, 1933).
Source: Who's Who Among North American Authors - Vol IV 1929-1930, compiled by Alberta Lawrence (Golden Syndicate Publishing Co., Los Angeles, 1929)
From http://www.flanderstoday.eu/living/canada-flanders-offers-solemn-tribute-countrys-role-first-world-war
“By the end of the war, some 619,000 Canadians had enlisted in the Canadian Expeditionary Force for service overseas. This was an enormous contribution from a country with a population of just under 8 million in 1914. Approximately 7% of the total population of Canada was in uniform at some point during the conflict, and hundreds of thousands of additional Canadians worked on the home front in support of the war effort.
While initially consisting mostly of white British-born Canadians, the Canadian Expeditionary Force also included other cultural groups: aboriginals of the First Nations, black Canadians and Americans, and even West Indians from the island of Bermuda.”
