MLA
Ramney, George. Drawing by John Rammey of "The John Neal Ante-Bellum Home on the Southwest Corner of Washington Street and Mitchell, General Sherman's Atlanta Headquarters, 1864". 1868. Stuart A. Rose Manuscript, Archives, and Rare Book Library, OP28, Folder 1. https://digital.library.emory.edu/purl/8773tx973n-cor.
APA, 6th edition
Ramney, G. (1868). Drawing by John Rammey of "The John Neal ante-bellum home on the southwest corner of Washington Street and Mitchell, General Sherman's Atlanta Headquarters, 1864" (OP28, Folder 1) [Paintings (visual works)]. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/8773tx973n-cor.
Chicago
Ramney, George. “Drawing by John Rammey of ‘The John Neal Ante-Bellum Home on the Southwest Corner of Washington Street and Mitchell, General Sherman's Atlanta Headquarters, 1864.’” Paintings (visual works). Civil War Collection, 1868. OP28, Folder 1. Stuart A. Rose Manuscript, Archives, and Rare Book Library. https://digital.library.emory.edu/purl/8773tx973n-cor.