The Constitution Act of 1867, originally known as the British North America Act, is a key piece of legislation that united the provinces of Ontario, Quebec, New Brunswick, and Nova Scotia into a single country called Canada. It established the framework for Canada's federal government, outlining the powers and responsibilities of both the federal and provincial governments. This act marked the beginning of Canada's journey toward self-governance, allowing for a parliamentary system similar to that of Great Britain. It also set the stage for future provinces and territories to join the federation, shaping the nation we know today.