The riveting hidden history of Claire McCardell, the most influential fashion designer you’ve never heard of.

Claire McCardell forever changed fashion—and most importantly, the lives of women. She shattered cultural norms around women’s clothes, and today much of what we wear traces back to her ingenious, rebellious mind. McCardell invented ballet flats and mix-and-match separates, and she introduced wrap dresses, hoodies, leggings, denim, and more into womenswear. She tossed out corsets in favor of a comfortably elegant look and insisted on pockets, even as male designers didn’t see a need for them. She made zippers easy to reach because a woman “may live alone and like it,” McCardell once wrote, “but you may regret it if you wrench your arm trying to zip a back zipper into place.”

After World War II, McCardell fought the severe, hyper-feminized silhouette championed by male designers, like Christian Dior. Dior claimed that he wanted to “save women from nature.” McCardell, by contrast, wanted to set women free. Claire McCardell became, as the young journalist Betty Friedan called her in 1955, “The Gal Who Defied Dior.”

Filled with personal drama and industry secrets, this story reveals how Claire McCardell built an empire at a time when women rarely made the upper echelons of business. At its core, hers is a story about our right to choose how we dress—and our right to choose how we live.