How many separate colonies united into Canada on July 1, 1867? The answer is three.
The three British North American colonies or provinces were the Province of Canada, Nova Scotia, and New Brunswick. They united under the British North America Act, 1867, creating the Dominion of Canada on July 1, a date now observed as Canada Day.
The wording can cause confusion because the Province of Canada was itself divided into two sections: Canada West and Canada East. At Confederation, those sections became the separate provinces of Ontario and Quebec. They count as two resulting provinces, but they were not two separate colonies joining the union on July 1; they were parts of the Province of Canada.
Prince Edward Island and Newfoundland did not join at the founding. Prince Edward Island entered in 1873, while Newfoundland joined in 1949. Canada therefore began with three participating colonies but four provinces: Ontario, Quebec, Nova Scotia, and New Brunswick.