MLA
Dillon, Edward. Telegram from Edward Dillon to Brigadier General Daniel Ruggles - July 14, 1862. 1862. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 6, Folder 6. https://digital.library.emory.edu/purl/2150gb5n8q-cor.
APA, 6th edition
Dillon, E. (1862). Telegram from Edward Dillon to Brigadier General Daniel Ruggles - July 14, 1862 (Box 6, Folder 6) [Telegrams]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/2150gb5n8q-cor.
Chicago
Dillon, Edward. “Telegram from Edward Dillon to Brigadier General Daniel Ruggles - July 14, 1862.” Telegrams. Civil War Collection, 1862. Box 6, Folder 6. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/2150gb5n8q-cor.