William Sherman Pène du Bois[a] (May 9, 1916 – February 5, 1993) was an American writer and illustrator of books for young readers. He is best known for The Twenty-One Balloons, published in April 1947 by Viking Press, for which he won the 1948 Newbery Medal. He was twice a runner-up for the Caldecott Medal for illustrating books written by others, and the two Caldecott Honor picture books, which he also wrote. [source](https://en.wikipedia.org/wiki/William_P%C3%A8ne_du_Bois)