Reform movement (pre-Confederation Canada)
In Upper Canada (Ontario), the Reform movement was formed in opposition to the Family Compact. It was led initially by William Lyon Mackenzie, who became the principal figure in the Upper Canada Rebellion of 1837. Mackenzie went into exile as a result of the failed rebellion. The uprising led to the 1839 Durham Report, which recommended responsible government and the union of Upper and Lower Canada as a means of assimilating Francophones. Only the union of the Canadas was to be immediately implemented.
Patriot War
While the initial rebellion in Upper Canada ended quickly with the Battle of Montgomery's Tavern, many of the rebels (including rebel leader William Lyon Mackenzie) fled to the United States. Mackenzie established a short-lived "Republic of Canada" on Navy Island in the Niagara River, but withdrew from armed conflict soon thereafter.