The Caldecott Medal has been awarded by the American Library Association since 1938 to the artist of the most distingushed picture book published in the U.S. in the preceding year. The logo you see pictured here was created by Brian Selznick. 

The first Caldecott medal was awarded to Dorothy P. Lathrop for the black-and-white lithographs she created for Animals of the Bible by Helen Dean. The 2013 medal winner is This Is Not My Hat, written and illustrated by Jon Klassen. (Publisher's Weekly article, "2013 Caldecott Caps Busy Year for Jon Klassen").

There are also 3-4 honor books awarded every year.

For a complete list of awards, you can check out the Caldecott Medal & Honor Books list.

The Hekman Library collects all of the award winners and most of the honor books as well.