Beginning with a discussion of the historical criticisms of American protectionism, this chapter moves quickly into a systematic review of the origins and arguments of protectionist political economy. The popularity and political influence of protectionism is indicated by the emergence of America as a bastion of nineteenth-century tariffs. Protectionism dominated nineteenth-century American economic discourse and was the essential expression of antebellum hybrid capitalism. By incorporating American exceptionalism, encouraging industrialization, celebrating the harmony between capital and labor, and pursuing methodological and theoretical values that were accepted across American culture, protectionism is presented as the most authentic manifestation of the antebellum economic mind. The economic ideologies of Alexander Hamilton, Matthew Carey, Daniel Raymond, Calvin Colton, and Friedrich List are explored. Each emphasized a nationalist concern in political economy, connecting political independence, especially from Britain, to national economic sovereignty.