Fashion designer Cristobal Balenciaga's "chemise" dramatically altered womenswear in 1957. Since Christian Dior's New Look in 1947, women wore extremely narrow waists, full wide skirts, and fortified busts. The supple shaping of Balenciaga's chemise, which draped in a long unbroken line from shoulder to hem, replaced the hard armature of the New Look. The chemise was a hit not only in couture fashion, where Yves Saint Laurent showed an A-line silhouette in his first collection for Dior, but also in Middle America, where Americans copied the simple shape which required far less construction and was therefore cheaper to make. Uncomfortable in the body conformity of the New Look, women rejoiced in a forgiving shape and the chemise, or sack dress, became a craze. The craze was parodied in an I Love Lucy episode in which Lucy and Ethel pine for sack dresses but end up wearing feed sacks.

Further Reading:

Chappell, R. "The Chemise—Joke or No Joke … " Newsweek. May 5, 1959.