"Yet while The Jungle remains a staple of American literature, The Brass Check has been all but forgotten. This is the case despite its groundbreaking critique of the structural basis of U.S. journalism, arguably the first such systematic critique ever made. Anticipating much of the best in more recent structural media criticism, Sinclair explained the class bias built into journalism in a four-part systemic model emphasizing the importance of owners, advertisers, public relations, and the web of economic interests tied into the media system, and invested in its control of public opinion. Integrating the critique of the press into the larger history of Progressive Era activism, Sinclair pointed to the centrality of the media in all of the problems of social injustice which attended the rise of modern capitalism."