The British North America Act, 1867 was a significant piece of legislation that united the colonies of Canada, Nova Scotia, and New Brunswick into a single Dominion known as the Dominion of Canada. This act marked the beginning of Canada's journey towards self-governance, establishing a federal system of government with a central authority and provincial governments. The act outlined the powers and responsibilities of the federal and provincial governments, creating a framework for governance that included a parliamentary system. It also provided for the admission of other provinces and territories into the Dominion, laying the groundwork for the expansion of Canada as we know it today.