This article clarifies the intellectual origins of Canadian parliamentary government by situating Confederation within a specific strand of liberal political thought. My argument is that the Fathers of Confederation adhered to the political theory of parliamentarianism. Though liberal constitutionalists, the Fathers of Confederation expressly defended a parliamentary political framework that they considered superior to the American system of checks and balances—one characterized by a powerful elected assembly restrained by an unelected upper house, responsible ministers serving in Parliament, and a constitutional monarch. In elucidating the theory of parliamentarianism that underlies the political project of Confederation, my goal is not only to examine a problem in nineteenth-century Canadian political thought but to ground our current political situation within a larger historical perspective.