Itsy Bitsy, Teenie Weenie, Yellow Polka Dot Bikini

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On this date in 1946 the bikini was introduced in Paris. Two-piece swimsuits had been in vogue since the early 1940s, although they were relatively modest and always covered the navel. In the summer of 1946 designer Jacques Heim came up with a revealing two-piece outfit which he called the atome: “the world’s smallest bathing suit.” But credit for the name goes to his competitor, French mechanical engineer-turned-swimsuit designer Louis Réard, who unveiled his design on July 5. He predicted that the skimpy swimwear would cause a cultural explosion to rival the recent nuclear tests at Bikini Atoll, and that’s where he got the name that stuck. Réard couldn’t find a model who was willing to wear such a revealing outfit so he had to hire an exotic dancer from the Casino de Paris. He got 50,000 fan letters and famously stated in his ads that a swimsuit wasn’t really a bikini unless you could pass it through a wedding ring.

It took a while for the bikini to catch on in the United States, however. Modern Girl magazine opined in a 1957 issue, “It is hardly necessary to waste words over the so-called bikini since it is inconceivable that any girl with tact and decency would ever wear such a thing.” But by 1960 it was big hit and singer Brian Hyland had a hit of his own that year, with the song “Itsy Bitsy, Teenie Weenie, Yellow Polka Dot Bikini.” In 1964 Sports Illustrated debuted its first swimsuit issue

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and by 1965 only “squares” went to the beach in anything but a bikini.
https://www.garrisonkeillor.com/radio/twa-the-writers-almanac-for-july-5-2021/

Meet the First Sports Illustrated Swimsuit Issue of the #MeToo Era

Image may contain Clothing Apparel Skin Nina Agdal Human Person Swimwear Bikini Lingerie and Underwear
Nina Agdal poses for Sports Illustrated’s 2017 Swimsuit Issue. By Ruven Afanador/courtesy of Sports Illustrated. https://www.vanityfair.com/style/2018/02/sports-illustrated-swimsuit-metoo-era