The article of clothing with which Katharine Hepburn is most closely associated is trousers. The actress’ fondness for pants—before they were considered ladylike—was not only a fashion statement but, to many, a symbol of stubborn independence and a declaration of modernity.
But many of Hepburn’s roles—and her legacy as a four-time Oscar-winning actress is certainly more notable than that as fashion trendsetter—required the woman LIFE called a “lanky, coltish thoroughbred” to adhere to more feminine standards.
For her 1939 Broadway turn in one of her most famous roles, socialite Tracy Lord in The Philadelphia Story, Hepburn hung up the pants and went all in on frilliness. LIFE described the process of designing her wardrobe:
Those creations featured silk-crepe and mousseline, flowing gowns and girdles. The extra effort, from wardrobe to performances, paid off. After a string of Hollywood flops earned her the unwanted label “box office poison,” Hepburn acquired the rights to the play, sold them to MGM, starred in the 1940 movie adaptation and revived her onscreen career.
Liz Ronk, who edited this gallery, is the Photo Editor for LIFE.com. Follow her on Twitter at @LizabethRonk.