Marvel Comics had first dipped into television with the daily, syndicated Marvel Superheroes show, which goes into the record books as the cheapest superhero cartoon in history. Marvel had their producing partners, Canada's Grantray-Lawrence Productions, animate actual panels from the books themselves. Only the opening & closing titles were fully animated. One of these fine days, I'll talk more about that.
In 1967, Marvel finally got the ball rolling, granting a license to Hanna-Barbera to adapt the Fantastic Four, and teaming once again with Grantray-Lawrence, this time for Spider-Man. Both series would last until 1970, brought back as mid-season replacements during the 1969-70 term.
Spider-Man stayed as true as possible to the books, but somewhere along the way, the series got a bit of a creative upgrade, as future icon Ralph Bakshi was brought in and Marvel severed ties with Grantray-Lawrence.
Just as iconic as the show itself is the theme song, performed by the Ray Ellis Singers. :
As we all know, Spidey would return again and again, having appeared in 4 more Saturday morning series, the last just three years ago. Most fans regard the mid-90's series for Fox to be by far the best of the lot. The 1967 edition falls somewhere in the middle.