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**American journalism is the subject of Upton Sinclair's book "The Brass Check."** Sinclair, an early 20th-century American writer and political activist, penned this influential work to expose the flaws and biases he perceived within the American press industry during the early 20th century. Through his investigative efforts, he sought to reveal how corporate and advertising influences can shape and distort news coverage, questioning the true nature of journalistic objectivity.