During King George's War, English colonial forces captured the French stronghold of Louisbourg on Cape Breton Island, Nova Scotia, but this gain was returned to France under the 1748 Treaty of Aix-la-Chapelle.

Canada was also an important battlefield in the Seven Years' War, during which Great Britain gained control of Quebec City after the Battle of the Plains of Abraham in 1759, and Montreal in 1760.

With the end of the Seven Years' War and the signing of the Treaty of Paris in 1763, France ceded almost all of its territory in North America. The new British rulers left alone much of the religious, political and social culture of the French-speaking habitants. Violent conflict would continue to arise during the next century, leading Canada into the War of 1812 and a pair of Rebellions in 1837.

In 1837, rebellions against the British colonial government took place in both Upper and Lower Canada. Their motivation was not so much anti-British and pro-Annexation (many of the rebels were themselves British in both Upper and Lower Canada). In Upper Canada, a band of Reformers under the leadership of William Lyon Mackenzie took up arms in a disorganized and ultimately unsuccessful series of small-scale skirmishes around Toronto, London, and Hamilton.

In Lower Canada, a more substantial rebellion occurred against British rule. Both English- and French-Canadian rebels, with some American backing, fought several skirmishes against the authorities. The towns of Chambly and Sorel were taken by the rebels, and Quebec City was isolated from the rest of the colony. Montreal rebel leader Robert Nelson read a declaration of independence to a crowd at Napierville in 1838. Les Patriotes, however, were defeated after battles across Quebec. Hundreds were arrested, and several villages were burnt in reprisal.

Despite the military defeat, the essential objective of the rebellions was later achieved because of the insurrections. This was when Lord Durham was sent to examine the situation and his Durham Report report strongly recommended responsible government. A less well received recommendation, however, was the amalgamation of Upper and Lower Canada in order to forcibly assimilate the French speaking population; The Canadas were merged into a single, quasi-federal colony, the United Province of Canada, with the Act of Union (1840).

Once the United States agreed to the 49th parallel north as the border separating it from western British North America, the British government created the Pacific coast colonies of British Columbia in 1848 and Vancouver Island in 1849, They were eventually united in 1866.

In 1867, with the passing of the British North America Act by the British Parliament, the Province of Canada, New Brunswick, and Nova Scotia became a federation, regarded as a kingdom in her own right. John A. Macdonald had spoken of "founding a great British monarchy" and wanted the newly country to be called the "Kingdom of Canada."Although Canada would maintain its monarch, officials at the Colonial Office in London, opposed this potentially "premature" and "pretentious" reference for a new country. They were also wary of antagonizing the United States which had emerged from the American Civil War as a formidable military power with unsettled grievances because of British support for the Confederate cause and thus opposed the use of terms such as kingdom or empire to describe the new country. As a result the term dominion was chosen to indicate Canada's status as a self-governing colony of the British Empire, the first time it would be so used in reference to a country.

With the construction of a the Canadian Pacific Railway, the new country expanded East, West and North, to assert its authority over a greater territory. A major means to achieve this was the foundation of the Northwest Mounted Police (now the Royal Canadian Mounted Police) which patrolled the territories. Manitoba joined the Dominion in 1870, and British Columbia in 1871. Westward expansion encountered serious resistance from the region's Métis inhabitants, in the form of the Red River Rebellion and the North-West Rebellion. In 1905, Saskatchewan and Alberta were admitted as provinces.

Canada's participation in the First World War helped create a sense of independence from Britain. The high point of Canadian military achievement came at the Battle of Vimy Ridge on April 9, 1917, during which Canadian troops captured a fortified German hill that had resisted British and French attacks earlier in the war. Vimy, as well as the success of the Canadian flying aces William Barker and Billy Bishop, helped to give Canada a new sense of identity. As a result of the war, the Canadian government became more assertive and less deferential to British authority, because many Canadians were dismayed by what they saw as British command failures.

Canada's involvement in the Second World War began when Canada declared war on Germany on September 10, 1939, one week after Britain. Canadian forces were involved in the failed defence of Hong Kong, the Dieppe Raid in August 1942, the Allied invasion of Italy, and the Battle of Normandy. Of a population of approximately 11.5 million, 1.1 million Canadians served in the armed forces in the Second World War. Many thousands more served in the merchant marine. In all, more 45,000 gave their lives, and another 55,000 were wounded. Countless others shared the suffering and hardship of war. By the end of the war, Canada had become a significant military power. However the Big Three paid little attention to Canada.

Conscription legislation was enacted during both wars (though on the initial promise of home-front service only in WWII) leading to increased tension between French and English Canadians. During the First World War, Prime Minster Borden's government enfranchised women who had close male relatives serving overseas, in the hopes of securing their support in the 1917 election.

Canada's economy grew in the aftermath of the Second World War, and its policies increasingly turned to social welfare, including hospital insurance, old-age pensions, and veterans' pensions. The economic boom resulting from wartime investment led the independent Dominion of Newfoundland into a period of transition. In a controversial series of referendums held in 1948, Newfoundlanders eventually decided to join in confederation with Canada. At the same time, Canada's foreign policy during in the Cold War was deeply connected to that of its neighbour to the south, demonstrated by the establishment an air defence system with the United States, NORAD.

In the 1960s, a Quiet Revolution took place in Quebec, increasing the tensions between Québécois nationalists and English Canada, until violence erupted during the 1970 October Crisis. During his long tenure in the office (1968–79, 1980–84), Prime Minister Trudeau attempted to reunify Canadian citizens.

As the highlight of his 1980s years as prime minister, Trudeau brought about the Patriation of the Canadian Constitution in 1982, which gave Canada a Charter of Rights and final independence from Britain. Unfortunately, the negotiations led to renewed antagonism between Quebec and the rest of Canada, which later Prime Minister Mulroney's Meech Lake Accord failed to smooth over. During the same decade, Canada engaged in violent conflict both abroad in the Gulf War and at home, during the Oka Crisis. Also this period saw the Mount Cashel Boys Home Scandal.

In the past decade and a half, Canada experienced the tenure of another one of the longest continuously serving prime ministers (Jean Chrétien), a second Quebec referendum on sovereignty, and the creation of a new territory, Nunavut. In 1993, the Canadian government set a target of 1% per capita population growth from immigration, the highest per capita immigration rate in the world. It should be noted, however, that by the standards of certain decades this is, in fact, a rather low rate of immigration. In 1913, for instance, Canada admitted 400,000 immigrants, equal to 5% of the population at the time.