Most of us know what it means to be a “good girl.” Good girls keep quiet, they do what they are told, they don’t complain, and they don’t talk back to the boss. They are definitely not  “troublemakers.”

In her book, The Good Girls Revolt: How the Women of Newsweek Sued Their Bosses and Changed the Workplace, author Lynn Povich provides a candid, step-by-step account of how, in 1970, she and 45 other women working at Newsweek went against their “good girl” upbringing and charged the magazine with discrimination in hiring and promotion.

These so-called good girls grew up under the strict social order of post–World War II America and came of age in the tumultuous 1960s. They were well-educated, talented, and largely apolitical. Many of them, like Povich, who went to Vassar, had degrees from one of the Seven Sisters schools. Back then, women like her, she writes, “were praised for their intelligence and commended for their capabilities but certainly not encouraged to have careers.”

At Newsweek, Povich and her female colleagues started in the mailroom or as fact-checkers and were ghettoized in the research department, while their male counterparts with identical credentials and résumés were groomed to be, or hired as, writers and editors.

Povich documents how the revolt was sparked during a consciousness-raising session; how it took root during clandestine meetings in the ladies’ room; and how, in its aftermath, some participants were promoted, while others weren’t ready for the increased opportunities or were unable to handle the suit’s resulting pressure and hostilities.

For her part, Povich became the first female senior editor at Newsweek in 1975, and went on to be editor-in-chief at Working Woman magazine and managing editor/senior executive producer for MSNBC.com.

The landmark lawsuit not only changed the system at Newsweek, it opened the door for similar actions at other publications. Eleanor Holmes Norton, the fiery civil rights attorney who initially took on the case, later told Povich, “because the women were so extraordinary, because the case was so clearly one of blatant, unmitigated discrimination, it made people understand discrimination against women in an important way.”

And yet, Povich doesn’t hesitate to remind us, “feminism isn’t finished.” Although her 25-year tenure at Newsweek ended in 1991, she opens the book in 2009 with Gen Xer Jessica Bennett, who, after starting work at Newsweek, suddenly encountered obstacles she couldn’t explain.

Eventually, Bennett and a few of her female colleagues—who were experiencing similar “obstacles” to their advancement while their male colleagues sailed up the ladder—learned about the case brought against the magazine almost 40 years before.

Until then, it hadn’t dawned on Bennett and her cohorts that these barriers were due to sexism. “Maybe it’s a female tendency to turn inward and blame yourself, but I never thought about sexism,” Bennett tells Povich. “We had gotten to the workforce and then something suddenly changed and we didn’t know what it was. After all, we had always accomplished everything we had set out to do, so naturally we would think we were doing something wrong—not that there was something wrong.”

It’s ironic that just as the groundbreaking lawsuit helped alleviate institutional sexism, it also cleared a path that allowed women like Bennett to see themselves as “post-feminist.”

Povich’s book reminds us that feminism remains relevant. Bennett and her colleagues were galvanized by their knowledge of the 1970 lawsuit. As a result, they pitched, and then wrote, an article (“Are We There Yet?”) that Newsweek eventually published in 2010, questioning how much had really changed for women both at the magazine and in the workplace over the last 40 years. Sadly, the statistics they cited spoke for themselves.

The piece received an overwhelmingly positive response from young staffers both male and female, writes Povich. After the story came out, she notes, “several women got promotions and there were more covers about women, written by women.”

That is why her documentation of the 1970 lawsuit is such a gift. It reminds us that we have the power to make change—we have only to use it, and that the fight for equal rights is uphill and ongoing.

As Harriet Rabb, one of the attorneys who worked on the case, says in the book’s epilogue,

 “It’s not over, and it’s never going to be over—the realization that people always have to have somebody who’s the other, that justice is so hard to come by, that fairness is so hard to come by. You hope that it will get better, and it does get better. But backsliding is so much easier than forward progress and there always has to be somebody who’s willing to step forward.”

I, for one, am grateful that back in 1970, Newsweek’s “good girls” had the courage to take that step.