Agitation for union or confederation of the colonies within British North America grew in the first half of the nineteenth century. After the rebellions of 1837-8, the colonies of Lower and Upper Canada were united in one government, the Province of Canada, with the Act of Union (1840), in a failed attempt to assimilate the French Canadians. Support for an even greater confederation was strengthened by events such as the Battle of Ridgeway, an invasion into Ontario by some 1500 U.S.-based Irish Fenian nationalists, an attack repulsed largely by local militia.
The Act of Union passed in July 1840 and proclaimed February 10, 1841, abolished the legislatures of Lower Canada and Upper Canada and established a new political entity the Province of Canada to replace them. This act effecting the political union of the Canadas was similar in nature and in goals to the other Acts of Union enacted by the British Parliament.
The British North America Acts 1867–1975 are a series of Acts of the British Parliament dealing with the government of Canada. The first and most important Act of the series was passed in 1867, and created the self-governing Dominion of Canada. Canada and the other British dominions achieved full legislative sovereignty with the passage of the Statute of Westminster 1931, but prior to the Canada Act 1982 the British North America Acts were excluded from the operation of the Statute of Westminster and could only be amended by the British Parliament.
British North American politicians held the Charlottetown Conference and Quebec Conference, 1864 to work out the details of a federal union. On July 1, 1867, with the passing of the British North America Act by the Parliament of the United Kingdom, three colonies of British North America (the Province of Canada, New Brunswick, and Nova Scotia) became a federation styled the Dominion of Canada. It consisted of four provinces, Ontario, Quebec, New Brunswick, and Nova Scotia.
In 1982 Canada patriated its constitution and entrenched within it the Canadian Charter of Rights and Freedoms, through the Constitution Act, 1982. By the Canada Act 1982, the British Parliament, acting at the request and with the consent of Canada, enacted the Constitution Act 1982, which established a procedure for the amendment of the Canadian constitution by the Canadian Parliament. The British North America Acts 1867–1975 are generally named Constitution Acts in Canada, and together with the Constitution Act 1982 are now collectively known as the Constitution Acts 1867–1982, though they remain named as they originally were in the United Kingdom. These and other Acts form the Constitution of Canada.
The Statute of Westminster 1931 was the enactment of the United Kingdom Parliament (December 11, 1931) which established the legislative equal status of the self-governing dominions of the British Empire and United Kingdom. (There exist also the unrelated Statutes of Westminster of 1275, 1285 and 1290 (known as First, Second and Third), passed by the parliaments of King Edward I.) The Statute is sometimes referred to, especially in the former dominions, as the Treaty of Westminster, although it was not in the form of a treaty. Today the Statute of Westminster is relevant for outlining the powers which Commonwealth Realms hold over any changes to the structure of their Monarchy.
The Statute applied to the dominions of Canada, New Zealand, Newfoundland, the Irish Free State, the Commonwealth of Australia, the Union of South Africa and except in relation to revision of the acts of parliament upon which the constitutions of Canada, Australia and New Zealand were founded. The Statute was expressed not to apply to Australia, New Zealand or Newfoundland unless and until adopted by those Dominions' Parliaments.
The Canada Act 1982 is an Act of Parliament passed by the British Parliament that severed virtually all remaining constitutional and legislative ties between the United Kingdom and Canada. It contains the text of the Constitution Act, 1982 of Canada in Schedule B.