This primary source comes from the Records of the Office of the Chief Signal Officer.
National Archives Identifier:
527817Full Citation: Inside of tent; ca. 1860 - 1865; Mathew Brady Photographs of Civil War-Era Personalities and Scenes, 1921 - 1940; Records of the Office of the Chief Signal Officer, Record Group 111. [Online Version, https://www.docsteach.org/documents/document/1-inside-of-tent, December 11, 2023]