The Big Red Dog celebrates the big 5-0

First-graders celebrate Clifford the Big Red Dog’s 50th anniversary Monday with his creator, Norman Bridwell (center rear); Bridwell’s daughter Emily Elizabeth (left); and Scholastic CEO Dick Robinson in New York.

NEW YORK — School kids sang “Happy Birthday” and Scholastic unfurled a huge banner worthy of a big red dog from the roof of its headquarters Monday to fete Clifford, the beloved book and TV character, for his 50 years of nudging kids to read.

His creator, Norman Bridwell, 84, took questions from a few dozen first- and second-graders during a webcast beamed live into more than 5,000 classrooms around the country from the party as tourists snapped photos from atop open-air double-decker buses stuck in traffic.

Bridwell’s daughter, Emily Elizabeth, spoke to reporters of her special place in publishing history as the inspiration for the perky, blond girl who shares her life — and 90 books of adventures — with the gawky, big-hearted Clifford.

She was just a year old when her father, a struggling artist from Indiana, and his wife, Norma, were trying to eke out a living in New York. It wasn’t going well when Norma suggested he try his hand at illustrating children’s books. Norma came up with the name Clifford, based on an imaginary friend she had as a girl.

But Bridwell’s 10 paintings for kids were roundly rejected. One staffer at a publisher told him if he wanted to work on children’s books, he’d have to write one of his own.

His story landed at Scholastic at a time the company was just starting in the trade fiction market. Clifford is now one of Scholastic’s most successful endeavors, with more than 126 million copies in print in 13 languages, a TV show and a multitude of products.

“I remember my mother was visiting from Indiana,” Bridwell said. “The baby had been crying all night and this woman called from Scholastic and said we’ve got this book here, ‘Clifford the Big Red Dog.’ We’d like to publish it.

“I never expected it to be accepted. My wife said after the first book, ‘Well, you could do more of these,’ and I said, ‘Don’t count on it. This is just a fluke.’ ”

Mayor Michael Bloomberg is a fan and declared Monday as Clifford the Big Red Dog Day.

Bridwell, of Martha’s Vineyard, Mass., had a simple vision when he dreamed up Clifford: He wanted to write about a dog as big as a horse. What he wound up with is a dog bigger than a house who shared some of the characteristics of kids. Clifford is red because that’s the color of the jar of paint Bridwell had nearby.

“I don’t really understand it,” he said of Clifford’s enduring nature. “Whether it’s his color, or if it’s the fact that he’s clumsy, like a lot of kids are clumsy. And a lot of kids would like to be forgiven for their mistakes, and Emily always forgives him when he makes a mistake.”

Emily Elizabeth, 51, of Carlisle, Mass., cites Clifford as part of the reason she became a preschool teacher. “As I got older and as I started to meet parents who really loved the books, they would express to me how much they meant to their family and how much they meant to their children. Then I started to realize it was something special.”