And a Little Bit of Pixie Dust

"The joke was on the Post gossip columnist, because Peter Pan collars were around for good: They’ve popped up as a fad in nearly every decade since Adams introduced the style. In the 1920s the collars became standard fare on little girls’ dresses, creating an innocent association that persists to this day. By the 1930s, the style had become nearly de rigeur at weddings—and not for the flower girls: Wedding announcement after wedding announcement in the ’30s and ’40s (even into the ’50s) describe the bride decked out in white satin and a Peter Pan collar. In the next two decades the look managed to swing smoothly from frumpy (First Lady Mamie Eisenhower wore a 'silky purple Molly Parnis dress [with] a Peter Pan collar' to her sixtieth birthday party in 1956) to hip (the New York Times described a young Lynn Redgrave in a 'black velvet see-through Mod dress with the white Peter Pan collar' in 1966)."

Julia Felsenthal in Slate presents a history of the Peter Pan collar.