Children's author who wrote and illustrated the Newbery Medal-finalist book, Olive's Ocean. He also received the prestigious Caldecott Medal for his 2004 work, Kitten's First Full Moon.
He wrote his first children's book, All Alone, at the age of twenty-one. In the next three decades, he wrote more than thirty other popular children's titles, including Lilly's Purple Plastic Purse and Chrysanthemum.
He graduated from the University of Wisconsin-Madison.
He and Louis Sachar were both nominated for the prestigious Newbery Medal.