Patriot's War

Following the independence of the United States, Canada remained under British control. The appointed executive and legislative councils in Lower Canada (Qu?bec) were largely dominated by the English-speaking merchant population. The councils continually clashed with the French-speaking majority in the Assembly. Louis Joseph Papineau led the francophone majority in the Assembly. In 1837 Papineau led radical reformers in military resistance against British authority, following several years of short wheat harvests. In Ontario, a group of people led by William Lyon Mackenzie, a Toronto newspaper editor and radical reformer (who was the city's first mayor in 1834), also rebelled.

When the rebels failed to overthrow the colonial governments, many of them fled to the United States. There they gained support for an invasion of the Canadas. British and Canadian troops clashed with American and Canadian troops along the U.S.-Canada border when returning Canadian refugees were joined by American sympathizers, notably in the Invasion of Prescott. The Battle of the Windmill focused on a seven story stone tower, originally constructed as a windmill, which was occupied by a party of American adventurers in November of 1838. It was one of many invasions by the United States that followed the unsuccessful Canadian rebellions in 1837. After the final battle took place at Fort Wellington near Prescott, Ontario, Canada, the rebellion failed and Papineau fled the colony.

These rebellions in Upper and Lower Canada in 1837 and 1838 prompted the British to join the two colonies, forming the united Province of Canada. In 1848 the joint colony was granted responsible government except in matters of foreign affairs.