What is Canada Day, and why all the celebration? On July 1, 1867, with passage of the British North America Act, the Dominion of Canada was officially established as a self-governing entity within the British Empire. The autonomous Dominion of Canada was a confederation of Nova Scotia, New Brunswick, and provinces of Ontario and Quebec. Two years after the passing of the British North America Act, Canada acquired the vast possessions of the Hudson’s Bay Company, and within a decade, the provinces of Manitoba and Prince Edward Island had joined the Canadian federation. In 1885, the Canadian Pacific Railway was completed, making mass settlement across the vast territory of Canada possible.