Papers, 1861–92, 4,100 items. U.S. senator, secretary of war, 1861–62, and minister to Russia, 1862. Correspondence and documents contain some information on Russian-American relations in the 1860s but this is only a small part of the total holdings. The entire collection has been microfilmed, for which microfilm edition there is a published finding aid. (NUCMC 64–1377)