The 1970s prom dress owes its look to one designer – Jessica McClintock. In 1967 Eleanor Bailey and Carol Miller established Gunne Sax – a boutique line of junior wear in San Francisco. The name was an amalgamation of ‘Gunny Sack’ (a burlap bag), and ‘sex’. Despite early success for their line of mod-inspired dresses, the two partners had a falling out and in 1969 Carol Miller left and Bailey sold the business to 39 year old Jessica McClintock.
McClintock’s look was very different – but her hippy-inspired granny-gowns with laced bodices and flounced skirts that resembled a combination of Medieval maiden and saloon girl were an instant success. The dresses became a standard of 1970s proms and weddings. Hillary Clinton wore a Gunne Sax wedding dress when she married Bill Clinton in 1975.
As the romantically styled calico gypsy/prairie dresses fell from favour in the late 1970s, Jessica McClintock’s style became more mature, and her name became the new label for the company. McClintock worked until her retirement in 2013, building the brand to include perfumes, accessories, bedding, furniture, and lighting. The brand was licensed and remains active with her son Scott managing the label. McClintock died February 16, 2021.
The New York Times wrote a very nice obit with more info.