In this public lecture, Jonathan Israel, Professor Emeritus in the School of Historical Studies, discusses the American Revolution and its enormous, but bitterly divisive impact on European (and Canadian and Latin America) political thought and attitudes. From 1776 began a furious ideological war within the USA over the question of democracy that helped precipitate an even more ferocious conflict between democratic and aristocratic forms of government in Europe. By the 1820s, it seemed that the aristocratic-monarchical system, led by Britain, had finally extinguished "Americanism" everywhere outside the USA. Modern representative democracy survived, as we know–but only just.