Bob Keeshan, 76, who entertained generations of children as the mustachioed star of "Captain Kangaroo," died Friday morning in Vermont after a long illness, a family friend tells CNN.

"Captain Kangaroo" debuted in 1955 and ran for 30 years on CBS before moving to public television, where it played alongside the likes of "Sesame Street" and "Mister Rogers" for six more years. The show won six Emmy Awards, three Gabriels and three Peabodies.

Captain Kangaroo -- so named for the kangaroo-like pouches in the pockets of the coat he always wore -- would wander through his Treasure House each day on the program, chatting with characters such as Mr. Green Jeans (played by Hugh "Lumpy" Brannum) and visiting with puppet animals like Bunny Rabbit and Mr. Moose.

When Keeshan first took the role, he was playing a character much older than he was. "I was impressed with the potential positive relationship between grandparents and grandchildren, so I chose an elderly character," he said, according to Reuters.

Keeshan was born in Lynbrook, Long Island, on June 27, 1927, and he served in the U.S. Marine Corp reserves before getting into broadcasting -- first working as a page at NBC, according to IMDB. He went on to portray Clarabell the Clown on the "Howdy Doody" show as well as hosting, emceeing and developing an number of other afternoon shows before launching "Kangaroo" in 1955.

He also was an author, publishing "Growing Up Happy" in 1989 and then "Good Morning Captain: 50 Wondering Years with Bob Keeshan, TV's Captain Kangaroo" in 1996. He also authored the "Itty Bitty Kitty" children's book series.

He was widowed in the late '90s and lived in New England.