When the War of 1812 began, the US government assumed that the Canadian colonies to the north would quickly grasp the opportunity to throw off British colonial rule and become part of the USA. Thomas Jefferson declared that Canada could be acquired simply by marching North.
It probably seemed a logical assumption. The colonies of Upper Canada (upstream along the St. Lawrence) and Lower Canada (downstream) were chafing at the British administration and the USA had 16 times as many people as the two colonies combined.
But there were factors that the USA did not reckon with. The largest ethnic groups in the USA have always been people of English and German descent. In Canada, the two main ethnic groups are the Scots and the French. The Scots and the English are not kissing cousins. The Scots have never graciously accepted English domination and this extended to the idea of domination by people of English descent from the USA.
In addition, a large chunk of the population of Upper Canada (now Ontario) consisted of United Empire Loyalists, people who had left (or been driven out of) the USA during the Revolutionary War because they did not agree with the idea of forcibly overthrowing the established government. These people were not enthused with the idea of once again coming under US authority.
The population of Lower Canada (now Québec) was largely French-speaking. They were not thrilled about being ruled by the British, but they did not see that being ruled by the Americans would be an improvement. At the battle of Chateauguay in October of 1813, 4,000 US invaders were put to flight by a French-Canadian battalion of 460 men, led by Lt. Col. Charles de Salaberry.
The Indian people of Canada were aware of the violence suffered by Indians in US territory and joined the battle to repulse the American invaders. They were joined by Tecumseh and a contingent of Shawnee warriors from the USA. Three times in his boyhood, US forces had destroyed the villages where Tecumseh lived, then in 1811 his community of Prophet’s Town, Indiana was burned to the ground.
A “Company of Coloured Men” fought in the battle of Queenston Heights. It is not hard to imagine that they had no desire to become part of the USA where they stood a good chance of being returned to slavery.
For these and many other reasons, the US invasion of Canada was a failure. Many Canadians consider the War of 1812 to be the birth of Canada as a nation. There were short-lived rebellions against colonial authority in both Upper and Lower Canada in 1837. This led to the granting of responsible government and the union of the two Canada’s in 1841. In 1867, New Brunswick, Nova Scotia and Prince Edward Island were united with Canada, followed by rapid western expansion and finally the addition of Newfoundland in 1949.
As a nonresistant Christian of Anabaptist-Mennonite persuasion, I am not seeking to glorify war. I find it worthy of note that wars often have consequences that are very different from the intentions of the party that instigated the war.