Jonathan Zimmerman teaches history and education at New York University. He is writing a history of sex education around the world.

In 1954, American Girl magazine published a book of beauty tips for young women. It included helpful suggestions about preparing for the ultimate American beauty contest: the high school prom.

“This is the moment to slip into your dress . . . Put your hair in place again, fasten your necklace or bracelet, and step into your pumps,” the book advised. “And wheee! Look now! There really is another you in the mirror. A you that is practically exuding a subtle new fascination, a wonderful femininity.”

I’ve been thinking about this passage as I watch my own daughter get ready for prom, which seems like a relic from another age. And maybe that’s the whole point of it. In a time of enormous flux and ambiguity in gender relations, this ritual returns us to a time when men were men and, yes, women were women.

The first recorded reference to a prom is from a student at Amherst College, who wrote in 1884 about attending prom at nearby Smith. But as more Americans joined the middle class, prom left the elite precincts of private colleges and filtered into the nation’s burgeoning secondary schools....