Explained | How US has tried to annex Canada before – and why some Canadians wanted to become American

Kristofer Allerfeldt for The Conversation

Exeter (England): “Canada never, ever will be part of America in any way, shape or form,” said Canada’s new prime minister-in-waiting, Mark Carney, after winning the race to lead the country’s Liberal party.

Carney’s message was a response to repeated statements from Trump in the past few months that he wanted Canada to become part of the US, and for the border between the two to be erased.

There is historical precedent to the idea of this specific land grab. Since its founding, the United States has frequently expressed an interest in merging with its northern neighbour.

Even before the United States had been formed, article 11 of the precursor to the Constitution, the Articles of Confederation, stated that: “Canada … shall be admitted into, and entitled to all the advantages of this union.” When the founding fathers signed the US constitution in 1787, Canada consisted of just Quebec, Nova Scotia and Newfoundland. The vast majority of the population was Catholic and French speaking. So, the idea of being absorbed into a new nation which had come into being driven by Puritan New Englanders was not appealing.

For Canadians it was bad enough to have been overseen from London, but at least the British parliament had guaranteed their rights with the Quebec Act of 1774. That tolerant measure allowed free practice of Catholicism, protected the use of the French language and even restored French civil law. In addition, at the time Canada’s fur, timber and fish trade was almost all with Britain, which had used a mix of tariffs and legislation to ensure the dominance of British ships.

Canadian traders could also take advantage of Britain’s Caribbean colonies importing cotton, rum and sugar in a circular trade. By the outbreak of the US revolution, Canada was well and truly sewn into Britain’s trading orbit, so Canadians resisted the siren song of the American revolutionaries.

But this did not stop American patriots from attempting to rally support for their cause in Canada. In May 1775 the American capture of Fort Ticonderoga, in upstate New York, spurred an invasion of Quebec. However, poor leadership, insufficient numbers and bad planning led to the defeat of the invasion in December 1775.

Another attack the following year had been rebuffed by the time the US had declared independence from Britain in July 1776. Americans would not attempt another invasion of their northern neighbour until their next war with Britain, in 1812.

The 19th century wars The 1812 invasion of Canada was a far more serious affair. Hoping to capture Canada in order to use it as a bargaining chip in their maritime disputes with Britain, US forces launched a three-pronged attack.

It met with stiff resistance from the British and their Canadian and Native American allies. The invading US forces were comprehensively defeated. They surrendered at Detroit on the western edge of Lake Erie. But even this would not be the last invasion by Americans.

During the US civil war (1861-1865) there was talk of forceable American annexation of Canada because of British support for the Confederacy, but it remained just talk. The year after that war ended, in June 1866, a group of 1500 Irish-Americans crossed the Niagara River into Canada.

There had been a precursor to this invasion when small bands of Irish-Americans launched a dozen or so raids on what was then the province of Upper Canada (today the southern half of Ontario) in the so-called patriot war of 1837-1838. However, the 1866 raid was arguably more like the 1812 invasions, in that the objective of the raid was to take Canada and use it as a bargaining chip for Irish home rule.

Initially the raid went well. The Americans defeated a small force of Canadian militiamen, but they were forced to withdraw back over the border when the British mobilised far larger forces. Undeterred, days later, the Irish launched another unsuccessful raid south of Montreal.

They would attempt another two invasions in May 1870 and a final raid in Manitoba in October 1871. All met with overwhelmingly superior Canadian forces, and never represented a serious threat.

While Canada would never experience another invasion from the US it was seen as a possibility in US strategic planning in the inter-war years. In 1927 the US department of war modelled a hypothetical conflict with Britain.

War Plan Red included invading Canada and devastating Nova Scotia using poison gas, as well as cutting Britain’s submarine cables to Halifax. Luckily, that war never happened, and invasion plans were shelved.

Since the US recognition of the Dominion of Canada in the Anglo-American treaty of Washington (1871) there hasn’t really been any serious talk of annexation until Trump renewed interest in 2024.. But there have been regional Canadians groups that have advocated joining the United States.

Canadians who wanted to be American In the 1840s, republican conservatives in Upper Canada sought to join the US as a way to improve democratic representation. The 1850s also saw American immigrants in Quebec advocate annexation to get away from French-Canadian dominance. Some British Columbians signed petitions to become Americans before it became a Canadian province in 1871.

The most notable movements of the 20th century were the Economic Union Party of Newfoundland in the 1950s and the short-lived Unionest Party in Saskatchewan in the 1980s. Both of these small parties saw advantages to some kind of union with parts of Canada and the United States, for economic reasons.

More recently, starting in the 1980s, a small political party, Parti 51, advocated that Quebec become part of the US, but failed to win much backing over the years. Its five candidates won 689 votes in Quebec in 2022. The party has now been dismantled.

An Ipsos poll of January 16 2025 found that nearly 80% of Canadians polled “would never vote for Canada to become part of the US”.

Maybe the current mood is best summed up by the Canadian New Democratic Party leader, Jagmeet Singh, who tersely told Trump: “Cut the crap Donald. No Canadian wants to join you.”

Kristofer Allerfeldt is an associate professor US History, University of Exeter.

Disclaimer: The views expressed above are the author's own. They do not necessarily reflect the views of DH.