Pity, if you can, the young women of today. Is there anything left for us that’s truly shocking? It’s all been done before – provocative clothing, illegal drinking, dirty dancing, and, of course, sex. Blame the flapper, girls. That “notorious character type who bobbed her hair, smoked cigarettes, drank gin, sported short skirts, and passed her evenings in steamy jazz clubs, where she danced in a shock ingly immodest fashion with a revolving cast of male suitors,” as Joshua Zeitz describes her, got there first.

Mr. Zeitz details it all in the first book-length study of the Jazz Age figure, “Flapper: A Madcap Story of Sex, Style, Celebrity, and the Women Who Made America Modern” (Crown, 352 pages, $24.95): the Prohibition-era speakeasies, the petting parties, the drink-fueled antics.

Many of the latter involve F. Scott Fitzgerald. He almost single-handedly created the flapper – or at least one could get that impression, given how the doomed figured looms over the book. If the “blond Adonis in a Brooks Brothers uniform,” as a contemporary called him, had never met the beautiful, wild Zelda Sayre, perhaps women would still be wearing corsets. He may not have invented the flapper. But with wife Zelda – “the first American flapper” – as his muse, the writer did more than anyone else to turn her into an icon.

He had some help, of course, and Mr. Zeitz’s lively history gives us the dirt on the illustrators, designers, movie stars, writers, and admen who sometimes lived the flapper life as they created and chronicled it. Lois Long, the New Yorker’s “resident flapper journalist,” is one of the most fascinating. The pseudonymous writer of a nightlife column, Long was once caught lying naked on a sofa in the New Yorker office with cartoonist Peter Arno, who may or may not have been her husband at the time.

There are plenty of other juicy anecdotes in “Flapper,” although those who know the period may be disappointed by the lack of fresh material. No one who’s done much reading on “Scott and Zelda,” as Mr. Zeitz likes to call them, will learn anything new about the ill-fated couple here. (Although for all his reading of the major biographies, Mr. Zeitz apparently never learned the odd spelling of Fitzgerald’s last mistress’s name, Sheilah Graham.)

What is original here is the voice of the ordinary flapper. Flapperism wasn’t simply a fashion choice. Work outside the home gave young women a sense of autonomy they were increasingly willing to take advantage of. They explain in their own words why they cast aside their corsets and curls in favor of cigarettes and cloche hats. “We were always fighting over my pay check,” one girl recalls of her parents. “Then I wanted to be out late and they wouldn’t stand for that. So I finally left home.” Another left for the bright lights of Chicago after a similar parental row. “I was always willing to stand up for my rights,” she explained.

That autonomy came at a price. While girls were freed from the shackles of the parental home, they also lost its protection. Mr. Zeitz says men first began to expect sexual favors in return for an expensive night on the town during the roaring ’20s. A larger-than-life woman like Coco Chanel may have effected a revolution in the way women dress. But when asked how she, a poor orphan, started an empire, she answered, “Two gentlemen were outbidding each other over my hot little body.” The revolution only went so far. (She never seemed bitter. When friends urged her to pay her models a living wage, she refused, declaring in a familiar French formulation, “Let them take lovers.”)

Mr. Zeitz isn’t as interested in those sorts of ironies as he is in another type. The 1920s are known as a prosperous decade for America, but Mr. Zeitz argues that few Americans actually shared in that prosperity. “For all their glitter and fascination, the 1920s were years of profound inequality,” he writes. “Upward mobility was redefined as the right to dress like the Rockefellers rather than earn like the Rockefellers.”

But it is hard to reconcile complaints about the average person’s buying power in the 1920s with details of all the products they con sumed. Mr. Zeitz gives us a mini-history of the advertising industry, explaining how our current commercial culture began. He regales us with a long list of items that even the small-town girls bought to look like the flappers they read about in the Saturday Evening Post and saw in movies like “Flaming Youth.” He details the new consumer products that just a few years earlier were nonexistent – mouthwash, ready-to-wear clothing, acne cream.

Working-class women were even more likely to experiment with new products such as cosmetics than their wealthier counterparts were. And minorities like blacks and Asians could buy in, too. It would have been nice if Mr. Zeitz had spent less time on the Scopes Monkey Trial and more on the interesting ethnic flappers, who merited only a few paragraphs.

Some things finally did affect buying power, however. The Depression was instrumental in bringing an end to the flapper era. The flapper’s sometimes ridiculous high jinks – Zelda Fitzgerald famously romped fully clothed through public fountains – seemed terribly inappropriate in the face of the country’s now-somber mood; she didn’t last long outside the 1920s. Her legacy, however, lives on. As Mr. Zeitz persuasively argues, “The flapper was, in effect, the first thoroughly modern American.”

Ms. Torrance is books columnist for the American Enterprise, arts and culture editor of Brainwash, and fiction editor of Doublethink.