ArchiveGrid [via OCLC]

ArchiveGrid is a database designed specifically for locating archival collections held in libraries, museums and other institutions. It combines all the archival records in WorldCat with others pulled from various archivesÂ’ Web sites. Included are all of the item records added to the National Union Catalog of Manuscript Collections (NUCMC) after 1987, as well as many records from earlier years. (NUCMC includes records added before 1987, especially of smaller archives, that are not found in ArchiveGrid.)