In 1872, Rockefeller and his associates used political corruption to secure an exclusive state charter that would have given them special advantages in dealing with certain railroads. The charter eventually was revoked, but while its fate remained uncertain, Rockefeller used it as leverage to eliminate his rivals by convincing them to sell their businesses rather than try to compete with him. In this way, Rockefeller succeeded in purchasing 22 of 26 Cleveland oil refineries in less than six weeks. This was the first step to monopolizing the entire oil industry.

Modern readers might associate oil with gasoline, but Rockefeller’s Standard Oil made its fortune first by refining crude oil into kerosene, an illuminant with a global market in the days before electric light bulbs became commonplace.

In the late-19th and early-20th centuries, the muckrakers were a group of reform-minded journalists who exposed everything from deplorable social conditions to political corruption. Ida Tarbell, author of the scathing 19-part exposé on Standard Oil that appeared in McClure’s Magazine beginning in 1902 and was eventually published as The History of Standard Oil (1904), ranks among the most influential of the muckrakers.