This paper maintains that American thinking on propaganda revolves around five approaches--progressive propaganda critics, media practitioners, textual rationalists, communication scientists, and political polemicists--that all have deep roots in the twentieth century social and intellectual history of the United States. The paper examines the schools and their periods of significant social and intellectual influence as well as dormancy, demonstrating a wide-ranging discussion about the implications for democracy of modern mass persuasion, and providing a broad panorama of ideological diffusion and competition in the United States. The paper's eight sections are as follows: (1) The Muckrakers and the Birth of Public Relations; (2) The Great War and the Furor over Propaganda; (3) The Communication Industry and Progressive Critique; (4) Responses by the Practitioners; (5) Communication Research; (6) The Rationalist Approach to Propaganda; (7) Propaganda and Polemical Competition; and (8) The Return of Progressive Propaganda Analysis. One hundred forty-two references are attached. (SR)