Elizabeth Janet Gray (1902–1999) was born and grew up in Philadelphia. She graduated from Bryn Mawr College, and in the years that followed, under the names Elizabeth Janet Gray and Elizabeth Gray Vining, she wrote many books for adults and children, including the Newbery Award winner Adam of the Road.   During and immediately after World War II, Elizabeth worked for the American Friends Service Committee. In 1946 she was appointed tutor to Crown Prince Akihito of Japan and later wrote the widely read Windows for the Crown Prince. She is the author of several novels and biographies and two autobiographical works.

Robert Lawson (1892–1957) received his art training at the New York School of Fine and Applied Art. His favorite medium, pen and ink, is used expressively and with detail in his black and white illustrations in The Story of Ferdinand (by Munro Leaf). In addition to illustrating many children's books, including Mr. Popper's Penguins, Lawson also wrote and illustrated a number of his own books for children. In 1940, he was awarded the Caldecott Medal for his picture book illustrations in They Were Strong and Good; and in 1944, he was awarded the Newbery Medal for his middle-grade novel Rabbit Hill.