Which British act established the Canadian Confederation in 1867?

The British North America Act established Canadian Confederation in 1867.

Passed by the Parliament of the United Kingdom, the Act united the Province of Canada, Nova Scotia, and New Brunswick into the Dominion of Canada. It received royal assent on 29 March 1867 and came into force on 1 July, now celebrated as Canada Day.

The Province of Canada was divided into Ontario and Quebec, giving the new federation four provinces. The Act also created Canada’s federal system, dividing powers between the central government and the provinces and establishing Parliament’s basic structure.

The statute is now officially called the Constitution Act, 1867. “British North America Act” remains the historically familiar name, so it is the canonical answer to this question. The Act of Union, by contrast, had united Upper and Lower Canada in 1840 but did not create the Canadian federation.