All the recent writing about 1950s haute couture got me thinking about my very first exposure to this dramatic art form, which for better and worse has been indelible: Lucy and Ethel in their burlap-sack dresses and feed-bucket hats, thinking they were all that on the boulevards of Paris. "Jacques Marcel"--the designer they believed created the gowns (which were in fact the fine work of Ricky and Fred)--was fictitious, but he could have stood in for a number of French couturiers who were at the time experimenting with waistless dresses.
Cristóbal Balenciaga was among the first--both in relaxing the fit across the back (inspired by the original "sacques", loose-backed gowns that were ubiquitious in the 18th century), and in elongating the line of a suit jacket right down to tunic length.
Others followed suit with a more form-fitting, though still essentially waistless dress. Writer Anita Loos enthused in Vogue about its alluring mystique: "no gentleman is ever going to puzzle his brain about the form of a girl in a Bikini bathing suit."
Whether it's down to the antics of Lucy and Ethel, or due to the classic expression "she could look good in a potato sack" (excellently demonstrated at left by Marilyn), Americans have always had a wary relationship with the sack dress. I'd love to know if that extends to other nationalities as well; I'm fairly certain that menfolk the world over, despite the reassurances of vintage Vogue, would tacitly prefer the bikinis.
(Balenciaga coat, 1957, photographed by Seeberger, Bibliothèque nationale de France, in The Golden Age of Couture; silk damask sacque gown from Southcoast Historical Associates)