This new research investigates the political controversies that swirled around a powerful and privileged state church and an aroused protestant and Catholic dissent demanding equality. Through close examination of dozens of electoral contests in several carefully chosen constituencies, the author demonstrates that the fundamental division separating the burgeoning liberal and conservative parties in England in the 1830s and 1840s was religion, and that this controversy was what created a perceptible two-party system in British politics.