Special Collections and Rare Books houses rare and unique materials that span over four thousand years. The collections include books, maps, posters, pamphlets, comics, artwork, artifacts, personal papers, and over 8 million titles on microform. Many of these materials are valuable primary sources.
The materials in Special Collections are here because they are fragile, one-of-a-kind, and they have lasting value for research. Because of this, the procedures for using books and other materials are a little different from what you may be used to in libraries. This guide will walk you through the process of finding and requesting materials in Special Collections.
Materials created or received by a person, family, or organization, public or private, in the conduct of their affairs and preserved because of the enduring value contained in the information they contain or as evidence of the functions and responsibilities of their creator, especially those materials maintained using the principles of provenance, original order, and collective control; permanent records.
Richard Pearce-Moses, A Glossary of Archival and Records Terminology, http://www2.archivists.org/glossary/terms/a/archives.
From "What is a Primary Source?" http://www.princeton.edu/~refdesk/primary2.html.