What national milestone is Canada Day the anniversary of?

Canada Day is the anniversary of Canadian Confederation.

Confederation took effect on July 1, 1867, when the Province of Canada—soon divided into Ontario and Quebec—joined Nova Scotia and New Brunswick to form the Dominion of Canada. The event was created through the British North America Act, now called the Constitution Act, 1867, and established Canada as a self-governing dominion within the British Empire.

The date is often called Canada’s birthday, but that phrase can oversimplify the country’s history. Canada’s sovereignty developed gradually: the Statute of Westminster in 1931 expanded legislative independence, while the Constitution Act, 1982 patriated the constitution and completed a major stage of constitutional independence. Canada Day originally had the official name Dominion Day and was renamed in 1982.

The Charlottetown Conference was an important planning meeting in 1864, not the national milestone commemorated on July 1. The Treaty of Paris and Statute of Westminster concern different moments in Canadian and imperial history.