Detail from the cover of From the Mixed-Up Files of Mrs. Basil E. Frankweiler

If you get the chance before September 7, make a point of checking out the New York Public Library’s exhibition “The ABC of It: Why Children’s Books Matter.” Even if you need no convincing on this score, you’ll love it: the exhibition is divided into a series of roughly chronological sub-categories—“Artistry of the Picture Book,” “From Page to Stage”—and illustrated with a wealth of amazing original sketches and manuscripts from iconic children’s books. Then there are the artifacts; you can see P. L. Travers’s parrot-head umbrella, and the original Winnie the Pooh stuffed bear, surrounded by his menagerie of equally well-worn friends.

If you are someone who loves children’s books, you may find yourself overwhelmed by the onslaught of Proustian reveries the show inspires. It feels a bit the way psychics say hospitals and graveyards feel to them—too many memories and associations and forgotten feelings clamoring to be heard at once. Certainly you will have to leave and come back.

I am sure I am not the only one who was especially riveted by one section in particular, on the children’s books of New York. There they all are: The Snowy Day, of course, and In the Night Kitchen, and The House on East 88th Street. (That’s the first Lyle Crocodile book.) And then there are the chapter books. Stuart Little,All-of-a-Kind Family,Roller Skates.

They had first editions of Harriet the Spy (1964) and From the Mixed-Up Files of Mrs. Basil E. Frankweiler (1967). It had never occurred to me that they had come out in such relatively quick succession—closely enough that one child might have read both on publication—or that, along with 1957’s The World of Henry Orient and maybe even Eloise, they formed a sort of subgenre of their own: the golden age of the Urban Child.

Everyone has read Louise Fitzhugh’s story of the independent-minded girl-spy who spends her days recording impressions of her uptown world, and the E. L. Koningsburg classic of two children who run away and live in the Metropolitan Museum. Henry Orientis probably better remembered these days as the inspiration for the 1964 Peter Sellers film. But like the other two, it chronicles the exploits of independent girls in Manhattan. As in the others, the girls are rich. They attend Brearley. Their parents are largely absent. Like Eloise and Harriet, they are raised primarily by nannies—a sort of midcentury take on the classic orphan narrative.

All these characters are complex, somewhat insolent, defiant, desperate for attention and love, and very much a product of their times. Theirs are inner lives created in reaction to the strictures that surround them. Their parents’ world is ruled by convention; the same privilege that creates their loneliness allows for the freedom of adventures. Heirs to Holden Caulfield? Probably—or maybe even Phoebe Caulfield. Within ten years, their parents’ society would have changed completely—and today both the freedom and the benign neglect that characterize the girls’ lives is as exotic as it is oddly appealing. The other thing that’s noteworthy about all these books is that, from a modern vantage point, we see the protagonists being screwed up before our eyes, and they don’t know it. Will these characters be okay? Not necessarily. Eloise, however, might have some good times with a few of her husbands.