MLA
Matthiessen, Frederic G. Reply from Matthiessen in Regards to Writ of Garnishment Issued to Him. 1862. Stuart A. Rose Manuscript, Archives, and Rare Book Library, Box 4, Folder 61. https://digital.library.emory.edu/purl/443nvx0m6m-cor.
APA, 6th edition
Matthiessen, F. G. (1862). Reply from Matthiessen in regards to writ of garnishment issued to him (Box 4, Folder 61) [Letters (correspondence)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/443nvx0m6m-cor.
Chicago
Matthiessen, Frederic G. “Reply from Matthiessen in Regards to Writ of Garnishment Issued to Him.” Letters (correspondence). Civil War Collection, 1862. Box 4, Folder 61. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/443nvx0m6m-cor.