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 read, and Spaulding provided Geisel with a similar list. Geisel later told biographers Judith and Neil Morgan that Spaulding had supplied him with a list of 348 words that every six-year-old should know and insisted that the book's vocabulary be limited to 225 words. However, according to Philip Nel, Geisel gave varying numbers in interviews from 1964 to 1969. He variously claimed that he could use between 200 and 250 words from a list of between 300 and 400; the finished book contains 236 different words. Geisel gave varying accounts of how he conceived of "The Cat in the Hat".