Ida Tarbell was a muckraker, although she preferred to call herself a historian. Actually, she was both. And amazingly good at both callings. A fellow writer once said: "She was beautiful with virtue—so good, so modest, so full of kindness, and able to infect her pages with her own shining love of truth."

Muck is dirt. Muckrakers were journalists who wrote about wrongs: about injustice, unfairness, and corruption. They wrote about the mighty industrial tycoons, about how some of them broke the law and got away with it, and why that cost the public great sums of money. The muckrakers developed a new kind of journalism—investigative journalism—just at a time when improved publishing techniques made it possible to produce a magazine, distribute it widely, and sell it for ten cents. Everyone seemed to read the muckrakers' articles. That made them very influential. They helped bring about change. Ida Tarbell was the most famous. A colleague, the progressive journalist Lincoln Steffens, once described her: "Sensible, capable, and very affectionate, she knew all our idiosyncrasies and troubles. She had none of her own so far as I ever heard."

When Ida Tarbell was a girl, she wished to be a scientist. She soon discovered that a degree and a passion for science were not enough: scientific research, like most fields, was a men-only domain. Ida became a teacher, but found she didn't really want to teach, so she went off to France. She had a little money and a lot of adventurousness, and she could write. That was what she was doing when Samuel McClure walked into her life.

Sam McClure was born in a two-room cottage in Ireland. When Sam was eight, his father died. The family had relatives in Indiana, so his mother took her three children to America. It was in Indiana, one Fourth of July, that young Sam heard a congressman give a speech. "He talked about the land of freedom, of unbounded opportunities," Sam wrote. "I had never heard such a speech before. I felt that, as he said, here was something big and free—that a boy might make his mark on those prairies."

At age fourteen, with a dollar in his pocket, Sam left home. He headed for Knox College in Galesburg, Illinois. But he didn't have enough money for college; so he worked, went to college, dropped out to earn more money, went to college, and worked some more. When he graduated, he went to Boston. Soon he was editing a biking magazine called Wheelman; he realized that what he really wanted to do was be an editor. In 1892 he founded McClure's Magazine. Not long after, he received an article from an unknown author about paving the streets of Paris. It was from Ida Tarbell. Sam McClure could spot talent. Tarbell was an outstanding writer. Eventually, Sam encouraged her to write a book about America's most powerful citizen, John D. Rockefeller, and his giant trust, Standard Oil.

Tarbell spent four years writing two books that were shockers. She showed how Rockefeller's Standard Oil Company took unfair advantage of its competitors. She showed how its uncontrolled power had spread into railroads, mining, and banking, and how that power affected the lives of most Americans. "Mr. Rockefeller has systematically played with loaded dice, and it is doubtful if there has ever been a time since 1872 when he has run a race with a competitor and started fair," she wrote. "Business played in this way is fit only for tricksters."

Three years after her books were published, the Supreme Court dissolved the trust of the Standard Oil Company. On its editorial page one newspaper wrote, "Miss Tarbell has done more to dethrone Rockefeller in public esteem than all the preachers in the land."

Ida Tarbell wasn't the only writer whom Sam McClure encouraged. He had a knack for finding good writers. "I had to invent a new method of magazine journalism," he said. His method was to pay writers well and let them do careful, lengthy research. Lincoln Steffens, by now also a McClure's writer, decided to investigate our cities. His articles became a book called The Shame of the Cities. Steffens went to Minneapolis, St. Louis, and Philadelphia and found corruption, lots of it. Most people assumed it was the poor who were the criminals in cities; Steffens showed that crime and graft were also found in the world of the middle class and rich. Because McClure's was so successful, other magazines began doing the same thing. It was a fine time for America's readers.