CN-6515 Treaty of Isthmus of Darien signing group photo, includes William H. Seward, 1869, Box: 1, Folder: 5. Mathew Brady photographs from the National Archives, RH PH 58. University of Kansas. Kenneth Spencer Research Library. https://archives.lib.ku.edu/repositories/3/archival_objects/407391 Accessed May 12, 2024.