It's not unusual that Norma Smallwood decided to wear a polka dot swimsuit because swimwear and polka dots have a history dating back to the 1800s when women wore swimsuits that looked more like short dresses and covered their legs with stockings and their head with a cap at the beach. For example, an 1884 picture in Harper's Bazar(that's how "bazaar" was spelled at the time) shows a woman in a swim dress with polka dots on the skirt, front placket, belt, kerchief tie, and sleeves. Her swim cap, also of polka dot fabric, matches the costume, which also has a pantaloon worn under the dress with polka dot decoration at the pant hems.
We usually think of polka dots as round spots being the same size with regular spacing between them, but Miss America's one-piece swimsuit shows an example of a pattern of both irregular size and spacing, which is sometimes also called polka dots.
