Ida Tarbell was an American writer and journalist who is best known for her 1904 book, The History of the Standard Oil Company. She was part of a group of muckrakers, or investigative journalists, who exposed corruption and injustices in the late 19th and early 20th centuries. Ida Tarbell and other muckrakers such as Upton Sinclair, Lincoln Steffens, and Jacob Riis were instrumental in bringing about social reform.