Populism undoubtedly has a long history in the politics of the US, and there is no doubt that populism has significantly affected American politics in a variety of ways. However, what exactly is meant by "populism" is frequently ambiguous and ill-defined. Political commentators routinely label individuals or ideas as populist, without even attempting to explain how and why the person or idea in question relates to populism. Scholars are not immune to acting in a similar fashion. Populism's presence is more often asserted than demonstrated in any convincing way. Here I engage in a thorough examination of the substance of populism in American politics. All elements of American populism -its championing of the common people, it rural roots, its anti-elitism, anti-intellectualism, and anti-government views, and its religious and cultural dimensions -will be explored. The paper closes with an attempt to suss out the place of populism in contemporary American politics.