The cocktail dress is an evening dress that is identified by its length. It can be anywhere from above the knee to about 7.5 cm (3 inches) above the ankle. The term lends itself to a variety of styles -- no sleeves, long sleeves, plain, printed, fitted or loose. The term "cocktail dress" was coined in 1935, although the "cocktail party" had been held long before then. The cocktail dress is suggested attire for a number of occasions, from its namesake, cocktail parties, to high-end restaurants and weddings.
In the 1920s, Prohibition took effect in America. People found creative ways to procure alcohol and to enjoy it. It was also around this time when women's clothing began a transition. Long, restrictive skirts gave way to shorter hemlines. Gatherings at speakeasies and at one another's homes created a new dress code that was neither too formal nor overly casual. The cocktail party had a more relaxed feel, and showing up in a long evening dress for a party where one mingled and walked about would not do.
The little black dress
In 1926, the familiar cut and silhouette of a typical cocktail dress was created. Coco Chanel debuted her little black dress. In "The Cocktail Dress," Laird Borrelli-Persson describes Chanel's iconic look, "a simple drop-waisted ebony frock embellished only with seams... it was an instant hit, and it has remained a classic cocktail dress style."
Later on, the little black dress and the cocktail dress would make for memorable moments in films and fashion images. Audrey Hepburn's knee-length black dress as Holly Golightly in "Breakfast at Tiffany's" is one of them. Another moment is in Alfred Hitchcock's 1954 film, "Rear Window." Actress Grace Kelly wears a cocktail dress with a full white chiffon skirt that ended just above her ankles. In typical 1950s fashion, she entered the room with her matching white gloves on.
In the 1950s the Rat Pack antics of Dean Martin, Frank Sinatra and company ushered an era of early evening cocktails and entertainment. This time around, the cocktail dress came with a list of complicated rules. For instance, guests had their hats and gloves on, but the hostess did not. Shoes that one wore during the day were not to be worn for evening occasions. The typical cocktail dress of the 1950s had a more modest length and neckline. Although the cocktail party was meant to be an informal gathering, the dress code itself and adhering to it was a serious matter.
For events that call for cocktail attire, a short length is the first thing that comes to mind. If anything, one should aim for a festive, semi-formal feel. Fabric choice may be dependent on what time of the year it is, but, other than that, all the other elements of the dress are open to one's own interpretation and personal style.