This primary source comes from the Records of the Office of the Chief Signal Officer.
National Archives Identifier:
529526Full Citation: Brady photograph outfit, going to the front; 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; National Archives at College Park, College Park, MD. [Online Version, https://www.docsteach.org/documents/document/brady-photograph-outfit-going-to-the-front, May 4, 2024]