Social Democracy and Society examines the origins of working-class radicalism in Imperial Germany. The Dusseldorf Social Democratic Party was associated with the left wing of the SPD. It defended theoretical orthodoxy against the onslaughts of revisionism, rejected all cooperation with bourgeois groups, and advocated militant tactics. Professor Nolan argues that the roots of this radicalism extended deep into the Imperial period and sprang from a confrontation between Dusseldorf's working class, which was variously young, highly skilled, migrant, and new to industry, and a political and cultural environment that offered no reformist options. She examines the distinct roles played by peasant workers new to industry, skilled migrant workers, and the indigenous population of Catholic workers. This is the first study to investigate in detail the history of the socialist labor movement in an urban area that was heavily Catholic and to analyze the significance of Catholicism for the political culture of the working class.