Tarbell went on to become a journalist, and she got a job at McClure’s Magazine, where the editor, S.S. McClure wanted his journalists uncover corruption and public abuse in American life. Ida Tarbell volunteered to take on Standard Oil, the company that had made her father’s life so difficult.

For two years, she interviewed everyone in the Pennsylvania oil industry who would talk to her, and she read every document she could get her hands on. It was Mark Twain who put her in touch with a Standard Oil insider named Henry Rogers, who provided her with all kinds of incriminating detail and evidence that Standard Oil was secretly colluding with railroad companies to charge smaller refineries higher rates to drive them out of business. She wrote 19 articles in all, and that exposé made her one of the most famous journalists in the country. Among her biggest fans was President Theodore Roosevelt, who went on to coin the term “muckrakers.”

John D. Rockefeller tried to ignore Ida Tarbell’s work at first. Then he said she was merely “misguided.” Finally, he began calling her “Miss Tarbarrel.” But it didn’t help. After her articles were collected into the book The History of the Standard Oil Company, the federal government began its antitrust prosecution of Standard Oil. The break up of the company was finally decided by the Supreme Court on May 15, 1911.