I will admit that I used the National Union Catalog of Manuscript Collections (NUCMC) long before I started working at the Library of Congress. It is a great way to locate information. Most of us now use ArchivesGrid, ArchiveFinder or one of many other resources to help users locate and gather information about the holdings at various repositories. Currently the program exists to provide service to very small institutions who do not have a lot of automation capacity and to support institutions that do not belong to OCLC or have other ways of contributing records to WorldCat or ArchivesGrid.
Peter Goodman, NUCMC Cataloger and member of the Cooperative and Instructional Programs Division of the Library of Congress provides additional information on NUCMC. I hope you will explore the NUCMC website and consider contributing to this important program.
The National Union Catalog of Manuscript Collections (NUCMC) is a free-of-charge cooperative cataloging program operated since 1959 by the Library of Congress in Washington, D.C. NUCMC catalogers create online records in OCLC WorldCat on behalf of eligible archival repositories throughout the United States. As of 2013, catalog records have been created describing approximately 130,000 collections in about 1,800 repositories.
As one of two NUCMC catalogers, I work with a variety of repositories (minority, special focus, religious, as well as state and local institutions) in 17 states. I maintain relationships with the repositories, which includes intake of new collections, asking questions as needed to catalog the material, and sending out finished records to the repositories. Knowledge of cataloging and authority control is essential for proper description of the collections.
During a typical day, I use paper finding aids as well as web-based information to create MARC records which are input directly into the OCLC WorldCat database. The completed records are available for researchers who can search either the local NUCMC “gateway” or OCLC’s ArchiveGrid. Based upon what they learn from the description of a collection in the NUCMC-supplied catalog record, the researcher can contact the repository and arrange to look at the material he or she needs, either in person or via facsimile.
I often conduct research online and in print resources to find information about names, places, dates, and other pertinent information to aid me in cataloging the collections. For example, I may have the papers of John Smith located at the Maine Historical Society. But which John Smith is he? Often, the repository will provide dates or other identifying information, but sometimes the clues are insufficient and I will do an online search to help me distinguish among the various John Smiths who may be the author or subject of the collection. Once I have that information, I can create authorized headings which will be inserted into the MARC record. The rest of the cataloging then follows: adding the scope note (the heart of the record–it tells the user what is contained in the collection), subject headings related to the collection, and other data that help the user locate the collection within the repository.
One of the repositories with which I work closely is the Moorland-Spingarn Research Center at Howard University here in Washington, D.C. This is a rich resource for African American history from the perspective of an important HBCU, which stands for Historically Black Colleges and Universities. Among the collections at Moorland-Spingarn is a large group of oral histories recorded in the 1960s and 1970s covering the civil rights movement. A subset of these oral histories concerns the Voting Rights Act of 1965 and the impact of that legislation on the men and women who shaped the civil rights movement. The recent news regarding the Supreme Court decision about the Act led me to prioritize the cataloging of those oral histories and make the records available to researchers around the country. The people interviewed include Rosa Parks, Vernon Jordan, Robert Kastenmeier, Hubert Humphrey, Jacob Javits, and many others, including several Members of Congress.
Working with NUCMC materials is challenging but also rewarding. I hope this brief summary provides you with a good overview of the important work NUCMC accomplishes for the U.S. archival community and researchers who use archives and primary source material.
Off the Record 
A number of repositories in Montana benefit from the work of the NUCMC catalogers. We thank them for their very valuable service.