The National Union Catalog (NUC) is a printed catalog of books catalogued by the Library of Congress and other 1,100 American and Canadian libraries, issued beginning in the 1950s.
The National Union Catalog is divided into two series: the Pre-1956 Imprints is a 754-volume set containing all older records in a consolidated alphabetical format, while post-1955 volumes continue to be published serially. Since 1983, the NUC has been issued on microfiche.
The National Union Catalog of Pre-1956 Imprints, a set of 754 volumes, largely superseded the older Library of Congress Catalog of printed books, and included printed works published before 1956 which are held by major American and Canadian libraries. It is sometimes referred to as the Mansell, after its publisher. This set is a massive bibliography compiled during the period from 1968 to 1981. It contains photocopies of printed catalog cards from major American and Canadian libraries, arranged alphabetically by author's last name, or by title for books that have no author, such as the Bible.
The NUC of Pre-1956 Imprints was an important resource for verifying bibliographic information and finding copies of books before the advent of large electronic bibliographic databases, such as WorldCat; the massive size and weight of the set make it less useful now. While online union catalogues provide easy access to bibliographic information, studies have shown that some old and rare titles are only recorded in the print NUC. For this reason it remains an essential tool for scholar
The National Union Catalog Pre-1956 Imprints: A Cumulative Author List Representing Library of Congress Printed Cards and Titles Reported by Other American Libraries, Compiled and Edited with the Cooperation of the Library of Congress and the National Union Subcommittee of the Resources Committee of the Resources and Technical Services Division, American Library Association
London: Mansell 1968-1981. 754 volumes.
You can consult the Print edition. (index by volume)
or the electronic edition by volume (Hathi Trust)
Below, we include the electronic access for each volume: