The Cat in the Hat Cat in the Hat" is the book that made Dr. Seuss famous. Without "The Cat", Seuss would have remained a minor light in the history of children's literature." Donald Pease concurs, writing, ""The Cat in the Hat" is the classic in the archive of Dr. Seuss stories for which it serves as a cornerstone and a linchpin. Before writing it Geisel was better known for the 'Quick, Henry, the Flit!' ad campaign than for his nine children's books." The publication and popularity of the book thrust Geisel into the center of the United States literacy debate, what Pease called "the
The Cat in the Hat for the series, including "The Cat in the Hat Comes Back" (1958), "Green Eggs and Ham" (1960), "Hop on Pop" (1963), and "Fox in Socks" (1965). He initially used word lists of limited vocabularies to create these books, as he had with "The Cat in the Hat", but moved away from the lists as he came to believe "that a child could learn any amount of words if fed them slowly and if the books were amply illustrated". Other authors also contributed notable books to the series, including "A Fly Went By" (1958), "Sam and the Firefly" (1958), "Go, Dog.