After swapping belle-époque frocks for men’s overalls to contribute to the war effort (you can’t do much heavy lifting in a tightly laced corset, after all), women shifted radically in the clothes they were willing to wear following World War I. Boned corsets and full skirts were out, and sleek shapes and relaxed fits were in. Naturally, it’s the knee-skimming flapper dress that remains the ultimate symbol of 1920s fashion,...