This primary source comes from the Records of the Patent and Trademark Office.
National Archives Identifier:
4531647Full Citation: Drawing of Improved Knapsack, Litter and Tent Combined; 7/7/1863; Records of the Patent and Trademark Office, Record Group 241. [Online Version, https://docsteach.org/documents/document/drawing-of-improved-knapsack-litter-and-tent-combined, June 3, 2023]