H. A. & Margaret Rey's Curious George first appeared on TV in 1980, although one would suspect that some of the books might've been read on the air before then by, say for example, Captain Kangaroo. Nickelodeon had the rights to this series of short cartoons, which now are lost to the mists of time. The cartoons were ultimately adapted into a new set of books. There is no real animation, so this would be similar to Nick's Video Comics (previously discussed) in that respect.
Obviously, when Universal adapted Curious George into an animated feature film in 2006, leading to the current PBS series, it was a large scale upgrade.
Right now, let's take a look at a sample episode from the 80's, "Curious George Walks the Pets".
I do remember seeing one or two of these back in the day after Nick was moved from a premium service to basic cable. I'll have to explain how that happened another time, but suffice to say, as I wasn't the target audience, I wondered why they couldn't afford to actually animate these stories.