He's always a mischievous kid at heart but, The Cat in the Hat turned fifty recently and was feted nationwide. To join in the fun, kids can send the Cat a birthday card from this Seussville site. Or consider a visit to the Dr. Seuss Memorial Garden in Springfield, MA, the author's birthplace.
According to the biography on the Cat in the Hat website:
"The Cat in the Hat, perhaps the defining book of Ted's career, developed as part of a unique joint venture between Houghton Mifflin (Vanguard Press) and Random House. Houghton Mifflin asked Ted to write and illustrate a children's primer using only 225 "new-reader" vocabulary words. Because he was under contract to Random House, Random House obtained the trade publication rights, and Houghton Mifflin kept the school rights. With the release of The Cat in the Hat, Ted became the definitive children's book author and illustrator."
The Dick and Jane readers that were commonly used at the time were lifeless and boring and so Dr. Seuss's rhyming, rollicking story of the subversive feline was a breath of fresh air in the world of children's books.