I just got through watching The Political Dr. Seuss, a documentary that I TiVoed on PBS last night. It's a very good program, being a biography of Ted Giesel viewed through the lens of his political activism, from his WWII political cartoons and work on army training films, through the allegorical stories of The Sneetches and Horton Hears a Who, to the more overtly political books near the end of his career, such as The Lorax and The Butter Battle Book.
Because his works didn't have speech balloons and were marketed as children's books, Giesel is often overlooked as the truly great cartoonist he is. For my money, he ranks right up there with Kirby as far as imagination and energy, and influence in his chosen genre. (He is also a forgotten luminary of science fiction, a case made in both this piece from Greg Beatty and in Paul Di Filipoo's essay "My Alphabet Starts Where Your Alphabet Ends." [found in Nebula Awards 24.])
The film is running on PBS this week as part of the Independent Lens series. If you aren't able to catch it, there's a companion Website you can visit. (And of course you can always go to your local library where you're sure to find the bulk of Dr. Seuss's oeuvre; provided it isn't checked out...)