Claim: The television series Secret Saturday by Canadian cartoonist Jay Stephens debuted in the United States on October 3, 2008, the first Cartoon Network original series in high-definition.
Evidence: The Secret Saturdays is an American animated television series created by Canadian cartoonist Jay Stephens for Cartoon Network. It debuted on October 3, 2008, in the United States. The Secret Saturdays was the first Cartoon Network original series to be broadcast in high-definition.