Events of National Historic Significance

The Events of National Historic Significance, also called National Historic Events (French: Les événements d'importance historique nationale), are events that have been designated by Canada's government, on the advice of the national Historic Sites and Monuments Board to the Minister of Environment and Climate Change, as being defining actions, episodes, movements or experiences in Canadian history. To be designated, an event must have occurred at least forty (40) years previous; events that continue into the more recent past are evaluated on the basis of what occurred at least 40 years ago.

Source: Wikipedia — Events of National Historic Significance (CC BY-SA 4.0)