British North America Act
British North America Act, law passed by the British Parliament in 1867 that provided for the unification of the Canadian provinces into the dominion of Canada. Until 1982 the act also functioned as the constitution of Canada. The act enumerated the powers of the provincial legislatures and gave the residual powers to the dominion; its interpretation by the privy council somewhat nullified this design by giving a very extended scope to the provincial power of "property and civil rights," and developing a doctrine of "emergency powers" to give the dominion the authority needed by a national government in time of war. This act was superseded by the Canada Act of 1982.