American painter, Civil War veteran, geological survey photographer, and an explorer (1843–1942) famous for his images of the American West. ALS signed “W. H. Jackson,” one page, 6 x 8.75, Explorer’s Club letterhead, no date. Letter to a gentleman. In part: “Drop in here at the Club at a time convenient for us to have either lunch or dinner together—I am pretty constantly in my room.” In fine condition. RR Auction COA.