Certainly the most popular of all American writers and illustrators of picture books, Geisel made his pseudonym Dr. Seuss famous to several generations of children and their parents. Geisel developed a rhythmic form of poetry that relied on quick rhymes and wordplay reminiscent of Mother Goose rhymes. He combined this with exaggerated cartoonlike illustrations of fantasy characters to entice children into stories that contained important messages, often presented with a great deal of irony and satire. Geisel always embraced the imagination of children and condemned adults' inability to join into it, using the child's view to reveal the flaws in society. His first picture book, And to Think… That I Saw It on Mulberry Street (1937), describes a child's adding more and more imaginative elements to the story that he plans to tell about what he saw on the way home, only to end with the child actually telling the truth: he saw only a very uninteresting horse and cart. The Cat in the Hat (1957), written as a beginning reader, portrays two children having a magical afternoon with a strange cat while their mother is away, complete with a frantic cleanup before their mother can find out what they have done. This is probably his most famous work. Geisel's later books took on social questions more directly. The Butter-Battle Book (1984) condemned the cold war, and it is often removed from children's sections of libraries for political reasons. Likewise, The Lorax (1971), which condemned the destruction of the ecology, has also been banned. Altogether, Geisel wrote and illustrated 47 books, which have sold more than 100 million copies in 18 languages. In 1984 he received a Pulitzer Prize for his contributions to children's literature. More than a dozen of his books are still in print.