Like the Family Compact, the Château Clique gained most of its influence after the War of 1812. Most of the families in the Clique were British merchants, although some were Anglicized French Canadians. Some of the most prominent members were brewer John Molson and James McGill, founder of McGill University. Generally, they wanted the French Canadian majority of Lower Canada to assimilate to English culture. This included the abolition of the seigneurial system, replacing French civil law with British Common law, and replacing the established Roman Catholic Church with the Anglican Church. Their efforts lead to the Union Act, which ultimately failed to assimilate all French Canadians but suceeded in preventing their political and economic interest to prevail on that of Britain.
The Constitutional Act of 1791 had established three branches of government: the Legislative Assembly, an elected lower house; the Legislative Council, an appointed upper house; and the Executive Council, which acted as a kind of cabinet for the lieutenant governor. The governor was always an appointed British nobleman, and he appointed members of the Clique as his advisors. The Clique was also able to establish itself in the Legislative Council, leaving the Legislative Assembly, made up of French-Canadian representatives, with little or no power.
Louis-Joseph Papineau, as a Reformer in the Assembly, was one of the fiercest opponents of the Chateau Clique. His struggles against the Clique and the Lieutenant Governor, Lord Gosford, led to the Patriotes Rebellion in 1837.
After the rebellion, Upper and Lower Canada were united as the Province of Canada, but the Château Clique did not disappear like the Family Compact did. While the English-speaking population became the majority, the British-appointed governors general still attempted to force the French Canadian population to assimilate. Canada East, as Lower Canada was called after the union, eventually gained some political independence with the union government of Robert Baldwin and Louis-Hippolyte Lafontaine.