The muckrakers were reform-minded journalists, writers, and photographers in the Progressive Era in the United States (1890s–1920s) who claimed to expose corruption and wrongdoing in established institutions, often through sensationalist publications. The modern term generally references investigative journalism or watchdog journalism; investigative journalists in the United States are occasionally called "muckrakers" informally.
The muckrakers played a highly visible role during the Progressive Era. Muckraking magazines—notably McClure's, of the publisher S. S. McClure—took on corporate monopolies and political machines, while trying to raise public awareness and anger at urban poverty, unsafe working conditions, prostitution, and child labor. Most of the muckrakers wrote nonfiction, but fictional exposés often had a major impact, too, such as those by Upton Sinclair.