Farm leader. Correspondence (1917–1934) with Simpson regarding Oklahoma Farmers Union and National Farmers Union policies, issues, stances, and activities, including financial papers and meeting minutes of the Farmers Union; Simpson’s nomination for the position of U.S. secretary of agriculture in Franklin D. Roosevelt’s first cabinet; Simpson’s opposition to President Herbert Hoover and his support of Al Smith’s candidacy for president; Simpson’s opinions regarding bimetallism, the National Farm Board, compulsory military service, and allegiance to the state; and condolences received by Simpson’s widow upon his death. Principal correspondents include Franklin D. Roosevelt, Huey P. Long, Henry Morgenthau, James A. Farley, and Elmer Thomas. Also in this collection are Simpson’s diaries (1924–1934); transcripts of radio and other speeches (1919–1933) delivered by Simpson; news clippings (n.d.); and newspapers (1917–1934), all relating to farm topics; and orders (1934) for Simpson’s book The Militant Voice of Agriculture.