This article explores how capital-labor relations were conceptualized in late nineteenth-century protectionist thought. Taking as an example the American Protective Tariff League (APTL), a national protectionist pressure group that was heavily influenced by industrial interests and attempted to popularize protectionist ideas by issuing newspapers, pamphlets, leaflets, and posters, it reconstructs the arguments protectionist industrialists used in their agitation targeted at industrial workers. Following the protectionist wage argument, the APTL made the supposed wage benefit to laborers in protected industries the center of their argument. This wage argument was strongly intertwined with nativist and Anglophobic stereotypes. Further, the APTL proposed a unity of interests between capital and labor in tariff matters that hinged on a nationalist interpretation of economic matters, in which the American national economy was conceptualized as being endangered by imports and competition from other national economies but simultaneously as a harmonious cooperation of capital and labor on the inside. Analyzing the organized labor movement’s response to such claims, the article argues that this sort of agitation, while important to industrialists’ arguments, probably had little influence on workers and their stance on the tariff issue.