The Caldecott Medal was named for Randolph Caldecott, an English illustrator of 16 picture books who was prominant in later ninteenth-century London. The Association for Library Service to Children, a division of the American Library Association, awards this medal every year to "the artist of the most distinguished American picture for children."
In addition to one annual medal winner, the selection committee also selects a few Caldecott honor books.
For more information: The Randolph Caldecott Medal