"Turn to any page of the recently published, two-volume, folio-size Catalog of the Cotsen Children's Library: The Nineteenth Century -- say, page 24 of volume II -- and the bibliographical detail accompanying each entry and illustration are case studies in thoroughness. In my case, page 24 reveals a charming, full-page, illustration of Theodore Léfèvre's Bébé saurait bientôt lire (approx. 1880), a hand-colored wood engraving frontispiece for an elementary reader. ... Among some of the treasures in the Cotsen's holdings include picture letters by Beatrix Potter, incunables, drawings by Edward Lear, and even an early-Coptic schoolbook."
- Barbara Basbanes, Fine Books & Collections

In fall 1996, the Cotsen staff began compiling a multi-volume book catalogue of the research collection, with support from the Department of Rare Books and Special Collections and the Technical Services Department of the Princeton University Library. These two volumes of the descriptive catalogue include more than 6,370 entries of 19th century illustrated children's books, continuing the series of printed catalogues first published in 2000 and 2003 covering 20th century imprints.

Following the Nineteenth Century volumes, the Pre-1801 Imprints and an Index were published in 2020 and 2021, respectively. Completed, the material comprises over 20,000 items chiefly in European languages out of a total over 100,000 items published during the fifteenth through twentieth centuries. The entries include detailed notes on illustrations, contents, bindings, and previous owners. As so many children's books appear without dates of publication on their title pages, every attempt has been made to assign an accurate date of issue based on internal evidence and authoritative reference sources in print and on-line. The text is enlivened with more than 270 color-printed illustrations, many full size.

Designed by Mark Argetsinger, these volumes are bound in mauve cloth and are uniform in design and production with the earlier volumes.