canada's first national internment operations of
1914 - 1920
On August 22, 1914, the Government of Canada enacted the War Measures Act, permitting the government to suspend civil liberties and to incarcerate “enemy aliens” – citizens of countries or empires legally at war with Canada.
Under the authority of The War Measures Act, Canada interned 8,579 such men, women and children – invited by Ottawa to settle the country and, in some cases, born here – in 24 internment camps from 1914 and 1920.
Another 80,000 were forced to register regularly with police officials. 
The majority of the affected were Ukrainians, targeted because they came from Bukovyna or Halychyna (Galicia),
then provinces of the Austro-Hungarian Empire.