One of the most popular ways of collecting childrens illustrated books in the United States is to collect first edition Caldecott Medal books.

The Caldecott Medal was named in honor of nineteenth-century English illustrator Randolph Caldecott who was one of the most influential artists of his time, along with Walter Crane and Kate Greenaway. His style captured such a sense of humour and vitality that it brought the books alive for his young readers.

The design on the Caldecott medal itself, is taken from one of his illustrations for the book called "The Diverting Story of John Gilpin". The artwork shows poor old Gilpin on his runaway horse among startled animals and spectators.

The medal has been awarded annually since 1938 by the Association for Library Service to Children to the artist of the most distinguished American Picture Book for Children published in the United States during the preceding year. The award only goes to an artist, who is a citizen or resident of the United States, whether or not he be the author of the text.

This form of collecting has become so popular it is not unusual for the first edition of even a fairly recent Caldecott Medal Book to fetch double its retail price, even if it was only printed in the last couple of years!
First editions of older Caldecott books consistently achieve treble figures and some of the early ones in fine condition reach the low thousands.