Muckraking is a term used to describe investigative journalism that exposes corruption and wrongdoing in politics, business, and other areas of society. It was popularized by American journalist and author Upton Sinclair in the early 1900s. Muckrakers often use their writing to uncover hidden truths and bring attention to issues that would otherwise remain unknown or ignored. The term has since been used to refer to any type of investigative reporting that seeks to uncover the truth and expose wrongdoing.