By fortunate coincidence, the possibility of a local union of colonies was under discussion at this very time in the Maritimes. A conference was convened in Charlottetown, P.E.I., in 1864 to discuss the question. Macdonald, accompanied by Brown and Cartier, headed a delegation from Canada to this meeting of their Maritime cousins. They set forth the possible advantages of a union wide enough to include the Canadas as well. It was quickly agreed that another meeting should be held to consider the plan further. The result was the Quebec Conference, which was held later the same year. Agreements in principle on the conditions that might permit so ambitious a union were finally reached. These agreements were summed up in the Seventy-two Resolutions.

As if to lend emphasis to the importance of such a union, the anti-British Fenians in the United States were voicing plans to strike a blow for Irish independence at home by invading the British colonies in North America. In 1866 this threat culminated in a series of raids across the border into Canada, which were successfully repulsed. The United States took steps to preserve its neutrality by suppressing further Fenian attacks from its side of the border. Some of the national spirit of 1812 to 1814 was rekindled in the British colonies and served to strengthen the movement toward confederation.

In 1866 representatives of New Brunswick, Nova Scotia, and the Canadas came together in London for final discussions with the Colonial Office. Newfoundland and Prince Edward Island for the moment had withdrawn from the confederation talks. The London Conference led directly to the most important statute in Canadian constitutional history, the British North America Act of 1867. This act, with its subsequent amendments, embodied the written constitution of Canada for more than a century. It was proclaimed on July 1, now celebrated as Canada Day.

The British North America Act provided that there should be four provinces in the new Dominion at the outset--Ontario, Quebec, New Brunswick, and Nova Scotia--and that others could join later. Each province was to have its own seat of government, its own lawmaking body, and its own lieutenant governor to represent the Crown. In addition, the act established a federal government at Ottawa, composed of a House of Commons (elected), a Senate (appointed for life), and a governor-general as the Crown's representative. It set forth the matters on which the provinces could make laws and listed those that were the special concern of the government at Ottawa. Any powers not listed were to belong to the federal government. (The act remained in force until the Constitution Act of 1982.)