Starting from the popular question formulated by Sombart in 1906 («Why is there no socialism in the United States?»), the article intends to present and discuss the problematic issue of American exceptionalism; the historiographical topos – not just American – which affirmed the existence of peculiar, unique, and exceptional qualities in the historical evolution and in the American political culture. The essay offers a historiographical reconstruction of the American Left in the late Nineteenth century and early Thirties of the Twentieth century, and follows out the main historiographical arguments on American exceptionalism, showing that these studies are based on the idea of a single and unique model of historical and political development, a Eurocentric model, characterized by a unhistorical and strongly deterministic perspective.
