Jonathan Zimmerman teaches education and history at New York University. He is the author of "Small Wonder: The Little Red Schoolhouse in History and Memory."

I went to three different summer camps when I was a kid, in the late 1960s and early 1970s. I swam, hiked and played sports (badly). And sometimes, I did nothing at all. That’s what summer — and camp — were all about.

But times have changed. About 20 years ago, so-called “specialty camps” began to replace the general-interest kind that I attended. So today you can go to camps that stress particular activities, from cooking and computers to robotics and rocketry.

Even at general-interest camps, meanwhile, kids are much more likely to receive professional athletic coaching, top-of-the-line art and music instruction, or even SAT-prep classes. Camp isn’t just for fun anymore. It’s about building a resume, a skill-set, a profile, a future. Like school, camp now prepares young people to win the great Race of Life.

Why?...