Chances are probably pretty good that you've never heard of Oliver Butterworth (May 23, 1915 – September 17, 1990). He didn;t write as many children's books as others I pay tribute to in this series, but his first book, The Enormous Egg, opened a door in my mind, showing me a whole new aspect of the imagination.
The whole idea of a chicken laying a dinosaur egg, and a boy about my own age raising a pet triceratops, as well as the struggles little Nate Twitchell had to endure against adults who wanted to claim the dinosaur for their own purposes, created a new world full of magic and interesting characters and conflicts.
I re-read The Enormous Egg a couple years ago and discovered something that went completely over my head as a kid. When Congress is debating whether Nate's dinosaur should be placed in the National Zoo, one congressman's blustery speech is one of the best pieces of political satire I've ever read. That this bit is hidden in a children's book helps to show the value books for young readers have in our society, and what adults miss when they grow "too old" to read kids' books.