Ida Tarbell grew up in the oil fields of northwestern Pennsylvania in the years after the first oil well was drilled there in 1859, a landscape of derricks, mud and boom towns. Her father made wooden tanks to store oil and later became an independent oil producer. When she was fourteen, a secret scheme between the railroads and a group of refiners, led by John D. Rockefeller’s Standard Oil, threatened to ruin independent men like him. She never forgot it.

She was the only woman in her class at Allegheny College, where she studied biology, then taught for two years and worked on a magazine. In her thirties she moved to Paris to write, supporting herself with freelance articles. There she caught the eye of S. S. McClure, who hired her for his new magazine, McClure’s. Her popular biographies of Napoleon and Lincoln, serialized in its pages, helped make it one of the most widely read magazines in America.

In 1902 she began the series that made her name. “The History of the Standard Oil Company” ran in nineteen installments over two years. Tarbell and her assistant spent years tracking down court records, legislative testimony and old newspapers to show, step by step and with documents, how Standard Oil had used secret railroad rebates, price wars and intimidation to crush its competitors and control nearly all the oil refining in the country. She even interviewed one of the company’s top executives, Henry H. Rogers, many times. She wrote coolly and precisely, letting the evidence carry the anger.

The series, published as a book in 1904, helped stir public opinion and government action, and in 1911 the Supreme Court ordered Standard Oil broken up. Tarbell’s method, of patient research in public records, became a model for investigative reporting.

President Theodore Roosevelt called writers like her “muckrakers,” after a character in The Pilgrim’s Progress who could only look down at the filth on the floor. Tarbell disliked the word. In 1906 she and several colleagues left McClure’s to run their own magazine. She kept writing and lecturing into her eighties, and she was, by her own choice, more cautious than many of her readers on some causes: for years she opposed votes for women.