Dr. Seuss, pseudonym of Theodor Seuss Geisel, (born March 2, 1904, Springfield, Massachusetts, U.S.—died September 24, 1991, La Jolla, California), American writer and illustrator of immensely popular children’s books, which were noted for their nonsense words, playful rhymes, and unusual creatures. After graduating from Dartmouth College (B.A., 1925), Geisel did postgraduate studies at Lincoln College, Oxford, and at the Sorbonne. He subsequently began working for Life, Vanity Fair, and other publications as an illustrator and humorist. In addition, he found success in advertising, providing illustrations for a number of campaigns. Geisel was especially noted for his work on ads for