One of the primary reasons for citing the sources of any research project is to ensure that a future reader or researcher may, if they choose, review the original source of the information and evaluate it for themselves.
To do this, a citation needs to adequately answer these two simple questions about the source: "What is it?" and "Where is it?"
This portion of the citation describes the nature of the source item. It should include as many of the following elements as are relevant:
This portion of the citation refers to the location where the archival materials can be accessed. It should include as many of the following elements as are relevant:
Information about how to cite the particular collection and the archival repository is often found in the collection's finding aid. At Special Collections & Archives, this information can be found in the Preferred Citation portion of the finding aid. However, it is still necessary to include in your citation additional details specific the particular item being cited and its whereabouts within the collection.
To determine whether you have included adequate citation information, ask yourself this question: Have I provided sufficient information to enable another researcher, archivist, or myself to locate that item again with relative ease? When in doubt, ask the archivist for assistance in identifying what information elements should be included in the citation, as well as accurately identifying that information.
If your professor or your field expects you to use a particular citation style guide (e.g., Chicago, MLA, etc.), then consult that guide directly for guidance in formatting the citation elements. Unfortunately, most citation style guides are relatively vague as to the precise details of citing archival materials. This is most likely due to the extremely varied nature of archival materials. In the allotted space of a citation style guide, it would be impossible to provide examples applicable to every archival item that exists.
Therefore, researchers are encouraged to cite as much information as would be necessary to locate the item again and to format the citation elements in a consistent manner. The citation usually lists "what" first, followed by the "where" in order from most specific to least specific: e.g., specific item, box and folder number, collection name and number, then repository information. If attempting to follow a particular citation style, model as much of the citation as possible after available examples within the guide. For the rest, do your best.