"The Brass Check: A Study of American Journalism" by Upton Sinclair is a muckraking exposé published in 1919. Sinclair investigates how American newspapers and wire services serve the financial interests of their owners rather than the public truth. Drawing from personal experience and documented cases, he reveals how journalists fabricate stories, suppress Socialist causes, and spread misinformation. The book proposes radical remedies including legal reforms and unionization. Sinclair called it his most dangerous work, refusing copyright to maximize its impact. (This is an automatically generated summary.)