September 13,
1969 was the day that the much-loved character Scooby Doo was first introduced to cartoon loving kids in the United States.
Our hero, Scooby Doo, a large red dog, and his beatnik friends Daphne Blake, Freddy, Velma Dinkley, and Norville "Shaggy" Rogers (voiced by internationally syndicated DJ Casey Kasem), travelled around the world in their bright green "Mystery Machine" van, getting into trouble ("You darn kids!!!) and solving mysteries ("Drats! Foiled again!).
In 1972 the wildly popular characters were given a one hour timeslot as The New Scooby Doo Movies, where the gang were given more time to solve even scarier mysteries, often assisted by guest stars such as Don Knotts, Dick Van Dyke, Don Rickles, Phyllis Diller and even Batman and Robin providing voice-acting. This was the progenitor format for later cartoons featuring guest actors such as The Simpsons.
The Scooby Doo franchise spawned a number of spin-off shows for it's creators Hanna-Barbera throughout the 1970s and 1980s, including The Scooby Doo Show.
The principal cast were:
Don Messick as Scooby-Doo
Casey Kasem as "Shaggy"
Stefianna Christopherson as Daphne (1969-1970)
Heather North as Daphne (1970)
Nicholle Jaffe as Velma Dinkley
Research sources include Perdedor, Warner Bros, TV Tome, joelb's Scooby Pages.