In 1841 the two colonies were re-united as Canada East and Canada West to try to reduce, if not eliminate, differences between the English and the French. The movement began to bind the British colonies together that would result in Confederation. Confederation came slowly, hesitantly, often with opposition and seldom with enthusiasm. The first significant discussions came in the early 1860s as a result of growing apprehension about the intentions of the expansionist Republic to the south and its policy of "Manifest Destiny".

Britain also wished to reduce its responsibilities of defending its surviving North American colonies.

In spite of strong opposition from the Atlantic colonies (Newfoundland and Price Edward Island withdrew from the negotiations) and uneasiness in Canada East (Quebec), the act of Confederation was passed in 1867. Modern Canada (Ontario, Quebec, Nova Scotia, and New Brunswick) was born.