This primary source comes from the Records of the Office of the Chief Signal Officer.
National Archives Identifier:
524572Full Citation: Wiard 6 lb. guns, Washington arsenal. Excelsior brigade; 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://docsteach.org/documents/document/wiard-6-lb-guns-washington-arsenal-excelsior-brigade, March 16, 2025]