The British North America Act takes effect as the Province of Canada, New Brunswick, and Nova Scotia join into confederation to create the modern nation of Canada. John A. Macdonald is sworn in as the first Prime Minister of Canada. This date is commemorated annually in Canada as Canada Day, a national holiday.

The Constitution Act, 1867, originally enacted as the British North America Act, 1867, is a major part of the Constitution of Canada. The act created a federal dominion and defines much of the operation of the Government of Canada, including its federal structure, the House of Commons, the Senate, the justice system, and the taxation system. In 1982, with the patriation of the Constitution, the British North America Acts which were originally enacted by the British Parliament, including this act, were renamed. However, the acts are still known by their original names in records of the United Kingdom. Amendments were also made at this time: section 92A was added, giving provinces greater control over non-renewable natural resources.

The Province of Canada was a British colony in British North America from 1841 to 1867. Its formation reflected recommendations made by John Lambton, 1st Earl of Durham, in the Report on the Affairs of British North America following the Rebellions of 1837–1838.

New Brunswick is a province of Canada, bordering Quebec to the north, Nova Scotia to the east, the Gulf of Saint Lawrence to the northeast, the Bay of Fundy to the southeast, and the U.S. state of Maine to the west. It is part of Eastern Canada and is one of the three Maritime provinces and one of the four Atlantic provinces. The province is about 83% forested and its northern half is occupied by the Appalachians. The province's climate is continental with snowy winters and temperate summers.

Nova Scotia is a province of Canada, located on its east coast. It is one of the three Maritime provinces and most populous province in Atlantic Canada, with an estimated population of over 1 million as of 2024; it is also the second-most densely populated province in Canada, and second-smallest province by area. The province comprises the Nova Scotia peninsula and Cape Breton Island, as well as 3,800 other coastal islands. The province is connected to the rest of Canada by the Isthmus of Chignecto, on which the province's land border with New Brunswick is located.