LOS ANGELES (AP) -- Now it can be told: "Sweet Caroline" is about Caroline Kennedy.

Neil Diamond held onto the secret for decades, but has now revealed that the inspiration for his smash hit was President Kennedy's daughter.

And he says he's happy to get it off his chest.

He tells The Associated Press he was inspired by a magazine photo showing the little girl dressed in her riding gear, next to her pony. He wrote the song in less than an hour in Memphis while holed up in a hotel.

Diamond says he never discussed it with anybody, but always thought he might "tell it to Caroline" someday. He got his chance last week when he performed the song by satellite at Caroline Kennedy Schlossberg's 50th birthday party.

The 40-year-old song recently reappeared on the singles chart, thanks in part to the Boston Red Sox. "Sweet Caroline" is played at every home game.

(Copyright 2007 by The Associated Press. All Rights Reserved.)