This primary source comes from the Records of the Office of the Chief Signal Officer.
National Archives Identifier:
524925Full Citation: Photograph 111-B-508; Pontoon Across Rappahannock River, VA (also Cavalry Column); ca. 1860 - ca. 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://docsteach.org/documents/document/rappahannock-pontoon, April 24, 2024]