Starting with the 1763 Treaty of Paris, New France, of which the colony of Canada was a part, formally became a part of the British Empire. The Royal Proclamation of 1763 enlarged the colony of Canada under the name of the Province of Quebec. The Constitutional Act 1791 split that Province of Quebec into two separate provinces, Lower Canada and Upper Canada, sometimes referred to the "Canadas". In 1841, the Union Act, 1840, Upper Canada and Lower Canada were joined to become the Province of Canada.

By the 1860s, interest developed in forming a new federation between the Canadas and the other British colonies of British North America, that led to Confederation in 1867. A number of other British colonies that are today part of Canada, such as Newfoundland and British Columbia, and large territories such as Rupert's Land, initially remained outside the newly formed federation.

New France under British rule

In North America, the Seven Years' War had seen Great Britain conquer the entirety of the French colony of Canada. The war officially ended with the signing of the Treaty of Paris on February 10, 1763. As part of the treaty, France formally renounced its claims to all its North American lands to Britain (of which the French colony of Canada was a part), except Louisiana (which had been instead ceded to Spain), and two islands off the shores of Newfoundland (Saint-Pierre and Miquelon).

St. Lawrence valley

With the addition of Canada to the British Empire, Britain gained control of a strip of territory along the St. Lawrence River with a population of at least 70,000 francophone Roman Catholics, which was expanded and renamed as the Province of Quebec under the Quebec Act of 1774. Although many British people (including the American colonies to the south) hoped the French Canadians would be assimilated this was not the case as distinct rules of governance for Quebec were set out in the Quebec Act such as allowing the French Canadians to retain their Catholic religion and their French system of civil law. The Quebec Act became one of the Intolerable Acts that infuriated the thirteen British colonies in what would become the United States of America.

Atlantic coast

The island colony of Newfoundland had been dominated by the British for a long time before the French finally abandoned any claims to the area. An anglophone society had already taken shape prior to 1763, although two islands were reserved for French fishermen.

In the Maritimes, the British had previously expelled many of the French colonists of Acadia in 1755 to Louisiana, but this would not be repeated in 1763. The remaining indigenous Mi'kmaq and Wabanaki Confederacy had laid down arms and pledged loyalty to the British Crown. The British Conquest of Acadia (which included Nova Scotia peninsula, but not present-day New Brunswick) happened in 1710, and the British had already established settlements, including Halifax. The establishment of Halifax sparked Father Le Loutre's War, which, in turn, led to the British expelling the Acadians from the region during the French and Indian War.Jobb, Dean (2005). The Acadians: A people's story of exile and triumph, Mississauga (Ont.): John Wiley & Sons Canada, 296 p. As they later captured Cape Breton Island and Prince Edward Island, the policy of expulsion was extended there as well. The few Acadians who managed to return to the area have created the contemporary Acadian society. Once the Acadians were expelled, other settlements were formed by New England Planters.

American Revolution

In 1775, American revolutionaries (Patriots) attempted to push their insurrection into northeastern Quebec. Support for the Patriot cause was mixed; the clergy and landowners were generally opposed to it, while English-speaking merchants and migrants from the Thirteen Colonies were generally supportive of it. The habitants were divided; in some areas (notably the region between Montreal and Saint-Jean), there was significant support, and militia companies were raised in support of the Patriots by James Livingston.

The Patriots laid siege to Fort Saint-Jean, capturing it and Montreal in November 1775. They then marched on Quebec City, where an attempt to take the city on December 31, 1775, failed. Following an ineffectual siege, the arrival of British troops in May 1776 sent the Patriots into retreat back toward Montreal. An attempt against British troops at Trois-Rivières failed, and the Patriots were driven from the province in June. Leaving with the rebel army were about 250 Québécois in two regiments: James Livingston's 1st Canadian Regiment, and Moses Hazen's 2nd Canadian Regiment.

Quebeckers living in the forts of the Great Lakes region also massively sided with the Patriots and were instrumental in the taking of the fort by the Patriots. Major Clément Gosselin, Pierre Ayotte, Antoine Paulin, Louis Gosselin, Germain Dionne, Pierre Douville, Edward Antill and Moses Hazen and 747 Quebec militiamen were all in Quebec when they joined the Patriots and defeated the British at Yorktown in 1781. In a key act leading up to the Siege of Yorktown, Louis-Philippe de Vaudreuil, the French-born nephew of French Canada's last French governor, the Marquis de Vaudreuil, assisted Bougainville and de Grasse in preventing the British Navy from resupplying or relieving Cornwallis' army in the Battle of the Chesapeake.

In Nova Scotia there was some agitation against British rule, largely instigated by Jonathan Eddy and John Allan, migrants from Massachusetts who had settled in the Chignecto Isthmus area near Fort Cumberland (formerly Fort Beauséjour). The only major event of their resistance was the Battle of Fort Cumberland, when Eddy and a combined force of Massachusetts Patriots, Acadians, and aboriginals besieged the fort in November 1776. The siege was broken and Eddy's forces were scattered when British reinforcements arrived. Eddy and Allan continued to make trouble on the frontier between what is now Maine and New Brunswick from a base in Machias for several years.

The Maritime provinces were also affected by privateering, and raids on settlements by privateers in violation of their letters of marque. In notable instances, Charlottetown, Prince Edward Island and Lunenburg, Nova Scotia were subjected to these raids.

In southwestern Quebec, the American forces had much better success there owing to the leadership of Virginia militia leader George Rogers Clark. In 1778, 200 men under Clark, supplied and supported mainly by Virginia, came down the Ohio River near Louisville, Kentucky, marched across southern Illinois, and then captured Kaskaskia without loss of life. From there, part of his men took Vincennes, but was soon lost to British Lieutenant Colonel Henry Hamilton, the commander at Fort Detroit. It was later retaken by Clark in the Siege of Fort Vincennes in February 1779. Roughly half of Clark's militia in the theatre were Canadien volunteers sympathetic to the American cause.

In the end, the British Empire was defeated in the Revolutionary War and formally ceded parts of southwestern Canada to the new United States as part of the Treaty of Paris. During and after the Revolution, approximately 70,000 or 15% United Empire Loyalists fled the United States, with the rest of the 85% choosing to stay in the new nation. Of these, roughly 50,000 Loyalists settled in the British North American colonies, which then consisted of Newfoundland, Nova Scotia, Quebec, and Prince Edward Island (created 1769). The Loyalists who settled in western Nova Scotia wanted political freedom from Halifax, so Britain split off the colony of New Brunswick in 1784. Quebec was also divided into Lower Canada and Upper Canada under the Constitutional Act of 1791, permitting the 8,000 Loyalists who settled in southwestern Quebec (which became Upper Canada) to have a province in which British laws and institutions could be established.

A number of Loyalists that came north after the American Revolution were of African descent including former slaves who had been freed as a result of service to the British and over 2,000 African slaves.James W. St. G. Walker, "Blacks" , in The Canadian Encyclopedia In 1793 Upper Canada became the first British jurisdiction to enact legislation to suppress slavery, with the Act Against Slavery being passed allowing for its gradual abolition.

Post-American Independence After the war the British expanded their mercantile interests in the North Pacific. Spain and Britain had become rivals in the area which came to a head with the Nootka Crisis in 1789. Both sides mobilised for war, and Spain counted on France for support; when France refused, Spain had to back down and capitulated to British terms leading to the Nootka Convention. The outcome of the crisis was a humiliation for Spain and a triumph for Britain, for the former had practically renounced all sovereignty on the North Pacific coast. This opened the way to British expansion in that area, and a number of expeditions took place; firstly a naval expedition led by George Vancouver which explored the inlets around the Pacific North West, particularly around Vancouver Island. On land, expeditions took place hoping for a discovery of a practicable river route to the Pacific for the extension of the North American fur trade, namely the North West Company. Sir Alexander Mackenzie led the first starting out in 1792 overland from Lake Athabasca via the Peace and Fraser Rivers, reaching the Pacific ocean near present-day Bella Coola on 20 July 1793. Mackenzie became the first European to reach the Pacific overland north of the Rio Grande which preceded the Lewis and Clark Expedition by twelve years. Shortly thereafter, Mackenzie's companion, John Finlay, founded the first permanent European settlement in British Columbia, Fort St. John. The North West Company sought further explorations firstly by David Thompson, starting in 1797, and later by Simon Fraser. These men pushed into the wilderness territories of the Rocky Mountains and Interior Plateau and all the way to the Strait of Georgia on the Pacific Coast expanding British North America Westward.

From 1783 through 1801, the British Empire, including British North America (but not India, which was under the East India Company, and later the India Office), was administered by the Home Office and by the Home Secretary, then from 1801 to 1854 by the War Office (which became the War and Colonial Office) and Secretary of State for War and Colonies (as the Secretary of State for War was renamed). From 1824, the British Empire was divided by the War and Colonial Office into four administrative departments, including North America, the West Indies, Mediterranean and Africa, and Eastern Colonies, of which North America included:

North America Upper Canada, Lower Canada New Brunswick, Nova Scotia, Prince Edward Island Bermuda, Newfoundland

The Colonial Office and War Office, and the Secretary of State for the Colonies and the Secretary of State for War, were separated in 1854, dividing the civil and military administration of the British Empire. The War Office, after 1854 and until the 1867 confederation of the Dominion of Canada, split the military administration of the British colonial and foreign stations into nine districts: North America and North Atlantic; West Indies; Mediterranean; West Coast of Africa and South Atlantic; South Africa; Egypt and The Sudan; Indian Ocean; Australasia; and China. North America and North Atlantic included the following stations (or garrisons):

North America and North Atlantic New Westminster (British Columbia) Newfoundland Quebec Halifax Kingston, Canada West Bermuda