Montpelier, Vt. ? Bob Keeshan, who gently entertained generations of youngsters as TV’s mustachioed Captain Kangaroo and became an outspoken advocate of less violence and more intelligence on children’s television, died Friday at 76.

Keeshan, who lived in Hartford, Vt., died of a long illness at a hospital in Windsor, his family said.

“Captain Kangaroo” premiered on CBS in 1955 and ran for 30 years before moving to public television for six more. It was wildly popular among children and won six Emmy Awards and three Peabody Awards.

Each day, the grandfatherly Captain Kangaroo — with his sugar-bowl haircut and a uniform coat with big pouch pockets that inspired the character’s name — would wander through his Treasure House, chatting with his good friend Mr. Green Jeans, played by Hugh “Lumpy” Brannum.

On the way, he would visit with puppet animals, like Bunny Rabbit, who was scolded for eating too many carrots, and Mr. Moose, who loved to tell knock-knock jokes.

Psychologist Dr. Joyce Brothers, who spent three seasons on the show, called it “a wonderful service for children and parents.”

“Parents could turn on the TV with complete security that what was shown wouldn’t be harmful in any way,” Brothers said.

Keeshan, born in Lynbrook, N.Y., became a page at NBC while he was in high school. He joined the Marine Corps in 1945.

His first television appearance came in 1948, when he played the voiceless, horn-honking Clarabell the Clown on the “Howdy Doody Show,” a role he created.

Bob Keeshan appears in character as Captain Kangaroo on the television show's set Oct. 19, 1981, in New York. Keeshan, who entertained and educated generations of children, died Friday, at 76, of a long illness.

“Captain Kangaroo” debuted on Oct. 3, 1955. After the PBS show ended in 1992, Keeshan continued to play the role for a time in videos and public appearances.

While the show felt like an impromptu walk through a child’s ideal playground, it was actually smartly scripted, said Peggy Charren, founder of Action for Children’s Television.

“He never did anything that would disappoint you,” Charren said. “He was a constant in lives that were not always full of constants.”

Keeshan, who moved to Vermont in 1990, also remained active as a children’s advocate, writing books, lecturing and lobbying. He criticized today’s TV programs for children as too full of violence. And he spoke wherever he went about the importance of good parenting.

Keeshan’s wife, Jeanne, died in 1990. He is survived by a son, two daughters and six grandchildren.