LOUDON — About 4,500 Scouts — boys and some girls — from New Hampshire, Maine, Vermont and Canada gathered this weekend for the Boy Scouts of America New Hampshire State Jamboree 2015 at New Hampshire Motor Speedway.

It was the largest group of Scouts ever assembled for a Daniel Webster Council jamboree, with about 1,200 new Scouts attending who had just been recruited, thanks to a new campaign that saw more Scouts recruited in one night in September than the council had recruited during any September in previous years, said Jackson Gaylord Jr., a council district director.

At the end of the day Saturday, the Scouts assembled to run their six-inch wooden cars, built from kits, in what was certified by the Guinness Book of World Records as the longest Pinewood Derby track — a half-mile — ever assembled.

It was the largest jamboree by far, as past jamborees, held every four years, brought about 2,500 Scouts at various venues. It was the first time the event was guest-hosted by the speedway.

"The kids are having a blast," said scout leader Patrick Grace of Strafford. "There's no way any one kid could go to all of the events we have here."

Some Scouts were throwing hatchets at targets or learning archery. Others were climbing artificial walls and jumping on bungee cords, while some were learning to weld or shooting off model rockets.

Maxwell, a 10-year-old Cub Scout from Dover, was shooting off his rocket when he stopped to talk to a reporter.

"I like the rockets, and I also learned to weld, which I thought would be dangerous but turned out to be fun," he said.

Gaylord said the jamboree was reaching the Scouts in ways that teachers and parents could not.

"Watch how much fun they are having," he said. "They don't realize that all of this fun is developing their character for life."