The muckrakers played a highly visible role during the Progressive Era.[1] 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.[2] Most of the muckrakers wrote nonfiction, but fictional exposes often had a major impact too, such as those by Upton Sinclair.[3]