The British North America Act (BNA Act) was passed by the British Parliament in 1867 and came into effect July 1 of that year, bringing together the colonies of Nova Scotia, New Brunswick, and Canada into a new political entity. The two divisions of the Province of Canada, formerly Upper and Lower Canada, became Ontario and Quebec respectively. The Act also made provision for the admission of additional provinces. Although it was a British statute, the BNA Act was drafted entirely by Canadians at the Quebec Conference of 1864 and passed without amendment. The preamble of the Act called for, “a Constitution similar in Principle to that of the United Kingdom.” The Act specified the composition of the Senate and House of Commons and the most important elements of the provincial constitutions.
For over a century, until the advent of the Charter of Rights and Freedoms, almost all cases in Canadian constitutional law arose from sections 91 and 92 of the BNA Act. These sections enumerated 29 areas of legislative jurisdiction that belonged to Ottawa and 16 areas that were reserved for the provinces (see Division of Powers). The Fathers of Confederation began section 91 with the so-called peace, order and good government clause that was intended to strengthen the central government by giving it control over anything not specifically granted to the provinces. A series of decisions by the Judicial Committee of the Privy Council reduced the clause to the status of an emergency power. Section 93, which entrenched the existing systems of Catholic and Protestant separate schools in the provinces, produced several bitter constitutional disputes in the late nineteenth and early twentieth centuries