The Children's Book Collection was established through the acquisition of several private collections, notably those of Elvah Karshner, Bernard M. Meeks, Olive Percival, May and George Shiers, and d'Alté Welch. The strength of the collection resides chiefly in English and American publications before 1840 and includes titles issued by such publishers as the Newbery family, John Harris, Benjamin Tabart, and Kendrew of York. Among authors represented in depth are Maria Edgeworth, part of whose own library is in the collection; Lady Fenn, writing as Mrs. Lovechild; Dorothy Kilner, writing as M. Pelham; and Mrs. Sherwood and Mrs. Trimmer, both prescriptive writers of the nineteenth century.
The English materials are supported by foreign-language editions, particularly Madame d'Aulnoy's fairy tales. Early games and pop-up and other movable books form a major segment of the collection, which includes the most extensive collection of harlequinades extant. The collection also includes some primary and secondary American textbooks, among them McGuffey readers and California textbooks. There is also a collection of modern juvenile books, including runs of the Newbery and Caldecott medal winners, and Russian children's books published between the two world wars.
Manuscripts supporting the collection include more than a hundred of Maria Edgeworth's letters and holographs of some of her stories; Mrs. Sherwood's manuscript journal, largely unpublished; the papers of Margery Fisher; and the papers and drawings of Lucille and Holling Clancy Holling.