The Lessing J. Rosenwald Collection stands out among the distinguished resources of the Library's Rare Book and Special Collections Division. Taking the illustrated book as its central theme, the collection's greatest strengths are in the 15th century woodcut books, early 16th century illustrated books, William Blake and 20th century lives of painters. Within this grand design the late Mr. Rosenwald sought books produced by the earliest printers and outstanding presses of later periods and books on the following subjects: science, calligraphy, botany and chess.

Among the characteristics that make this collection such a rich potential resource for study are the presence of an amazing number of unique books and books of such great rarity that only a handful of copies is known. Virtually every book in the collection is in superb condition. Rosenwald's assemblage of books, plates, drawings and engravings by English artist, poet and mystic William Blake is one of the finest ever brought together. Of the 20 illuminated books described in Geoffrey Keynes's Blake bibliography, the collection contains 14, as well as duplicates and extra plates.

A selection of materials from the collection is online in "Digital Materials from the Lessing J. Rosenwald Collection."