Answer:
The Jungle, novel by Upton Sinclair, published serially in 1905 and as a single-volume book in 1906. The most famous, influential, and enduring of all muckraking novels, The Jungle was an exposé of conditions in the Chicago stockyards. Because of the public response, the U.S. Pure Food and Drug Act was passed in 1906, and conditions in American slaughterhouses were improved.