From the 16th to the early 18th century "Canada" referred to the part of New France that lay along the Saint Lawrence River. In 1791, the area became two British colonies called Upper Canada and Lower Canada collectively named the Canadas; until their union as the British Province of Canada in 1841. Upon Confederation in 1867, Canada was adopted as the legal name for the new country at the London Conference, and the word Dominion was conferred as the country's title. By the 1950s, the term Dominion of Canada was no longer used by the United Kingdom, which considered Canada a "Realm of the Commonwealth". The government of Louis St. Laurent ended the practice of using Dominion in the statutes of Canada in 1951. In 1982, the passage of the Canada Act, bringing the Constitution of Canada fully under Canadian control, referred only to Canada, and later that year the name of the national holiday was changed from Dominion Day to Canada Day. The term Dominion was used to distinguish the federal government from the provinces, though after the Second World War the term federal had replaced dominion.