Archive Finder brings together ArchivesUSA and the cumulative index to the National Inventory of Documentary Sources in the UK and Ireland (NIDS UK/Ireland).
ArchivesUSA is a current directory of over 5,600 repositories and more than 175,000 collections of primary source material across the United States. NIDS UK/Ireland is a major reference work that reproduces the finding aids to thousands of archive and manuscript collections in libraries and record offices, museums and private collections throughout the UK and Ireland. Used together in Archive Finder, researchers are able to read descriptions of a repository's holdings to determine whether a collection contains material useful to their work as well as find the information they need to contact the repository directly.