This is the first comprehensive study on the relationship of propaganda to participatory democracy in the United States during the twentieth century. The Muckrackers were the first critics to question whether the standard practices of communications industries, such as advertising and public relations, undermined the ability of citizens to gather enough reliable information in order to participate meaningfully in society. The communications industry has countered that propaganda merely circulates socially useful information in an efficient manner and further, that propaganda is harmless to democracy because of competition and professional codes. This study critically examines these various schools of thought in an effort to determine and understand the contribution and effects of propaganda in a democratic society.