Why did the provinces of British North America desire to unite into a dominion under the British government?

also called Constitution Act, 1867, the act of Parliament of the United Kingdom by which in 1867 three British colonies in North America—Nova Scotia, New Brunswick, and Canada—were united as “one Dominion under the name of Canada” and by which provision was made that the other colonies and territories of British North America might be admitted. It also divided the province of Canada into the provinces of Quebec and Ontario and provided them with constitutions. The act served as Canada’s “constitution” until 1982, when it was renamed the Constitution Act, 1867, and became the basis of Canada’s Constitution Act of 1982, by which the British Parliament’s authority was transferred to the independent Canadian Parliament.

Explanation:

i really do want to but i just don't know it i'm so sorry : (

maybe i can