The MLA Handbook, Ninth Edition, from 2021, is the current official source for the MLA Style. The publication does not list rules on how to cite specific archival material.
For general guidance on how to cite archival material, you should follow the MLA format template that applies to publications and other conventional sources.
Jennifer Rappaport's online document “A Guide to Citing materials from Physical Archives and Collections” has examples on how to cite selected archival material using the MLA Style.
When you view digitized archival sources made available online and cite them using the MLA Style:
Additional information is available in the online document "Citing Artifacts in a Digital Archive".
General format for Works Cited
Author’s surname, author’s name. Title. Document’s date in Day month year format. Collection name, Accession Number, Box Number, Folder Number, Archive name, Location. URL or DOI if applicable.
When it comes to the list of cited works, the MLA Style is based on a system of core "elements" or pieces of information, such as author, title, publisher, publication date, and location, that are common to most conventional sources like publications. These elements are presented in a specific order in the Works Cited list.
An item from the archives, such as a letter or a photograph, is usually part of something larger like a collection. This collection may be considered a container with slots that hold specific pieces of information. The collection's name becomes the container's title, and the item's specific details like Accession/Box/Folder Number are listed in the location slot of the container, either before or after the institution. The examples in this guide will list an item's specific details before the institution's name, in this case the University of Regina Archives & Special Collections.
Sometimes you may be missing some of the elements, for instance when a photograph's creator or title (or both) are unknown. In such cases you can skip this information and start your entry with a title, or provide a brief description of the item in the absence of an author and/or title.
General format for In-text Citations
(Author’s surname Page)
The MLA Style follows the author-page method of in-text citation. The author’s surname and page number appear in parentheses in the running text as part of the sentence.
Omit the page number if it's not applicable, as in the case of a photograph or a single page letter. If the author/creator is unknown, substitute the surname with the item's title or brief description, in parentheses after the cited or paraphrased text.
If in your paper you cited several works or archival items by the same author, in the parentheses add a shortened title or year for each citation in order to differentiate between multiple sources.
Works Cited
Department of English. Annual Report. 1970-1971. Department of English fonds, 2014-54, Box 1, File 1, University of Regina Archives and Special Collections, Regina, SK, Canada.
In-text Citation
(Department of English 1)