Before he was a children's illustrator and author, Theodore Geisel (later, better known under his pen name, Doctor Seuss) worked as a political cartoonist, and many of his cartoons criticized America's lack of involvement in the early days of World War II.
What an interesting display this was. You could definitely see that Seuss had already developed his trademark style. Here's one of his political cartoons. Pencilled in, too faint to see in this photo, is the caption, "Stop wringing the hands that should wring Hitler's neck!"
Here's another. The caption for this one read, "...and the Wolf chewed up the children and spit out their bones... but those were Foreign Children and it really didn't matter."
Here's something you don't see often. A young, unbearded Theodore Geisel!
There was a fantastic Seuss playground, featuring some of the characters from his books most famous for promoting social justice: Horton Hears a Who, The Sneetches, The Butter Battle Book and Yertle the Turtle. Fun stuff! McBean's machine from The Sneetches was really something else... it has a flashing light and sound effects when you go through it.