World War I

Canada automatically goes to war when Britain declares war on Germany on August 4, 1914 with the first troops leaving for Europe on October 3. During this time, the War Measures Act is passed allowing the suspension of civil rights during periods of emergency.

On April 22, 1915, Canadian soldiers face a German gas attack at Ypres, Belgium. Also, during the year, John McCrae writes In Flanders Fields. In August 1916, the Canadian-made Ross rifle is withdrawn from war service.

In 1917, income tax was introduced as a "temporary wartime measure." On February 23, Prime Minister Robert Borden sits as a member of the Imperial War Cabinet to give Canada a voice in war policy. Canadians would capture Vimy Ridge in France during April 9 to 12. On June 11, the Military Service Bill is introduced leading to the Conscription Crisis between Quebec and the rest of Canada. Canadians take Passchendale, Belgium on November 6 in one of the war's worst battles.

On August 8, known as "the black day of the German army," Canadians break through German trenches at Amiens. From this period until the end of the war is known as "Canada's Hundred Days."