Upton Sinclair, Ida Tarbell and Frank Norris were amont the first journalists to publicize immoral, corrupt practices of large industries during the Progressive Era.
Upton Sinclair was an American writer who won the Pulitzer Prize. In 1904, Fred Warren, editor of the socialist newspaper Appeal to Reason, commissioned him a report on the bad practices of the food industry that would become the novel The Jungle, an unprecedented sales success and a huge international commotion. As a consequence, President Theodore Roosevelt received the author in the White House and put in place laws to ensure the quality of food for human consumption.
Ida Tarbell was an American professor, writer and journalist, considered one of the main "muckrakers" of the Progressive Era. She is known for her research on John D. Rockefeller and the Standard Oil Company; her investigations exposed the unfair monopolistic practices carried out by the company until the Supreme Court decided to dissolve the monopoly.
Frank Norris was an American correspondent and novelist. Between 1895 and 1896, he worked as a correspondent in South Africa. Between 1896 and 1897, he was assistant editor of the San Francisco Wave. During the Spanish-American War, Norris was a correspondent in Cuba for McClure's magazine, being critical of American interventionist policies in the war.