The Wheeler collection consists of thirteen series: General Correspondence (1923-1972), Miscellaneous Correspondence (1924-1956), Campaign Materials (1922-1946), Court Papers (1920, 1924, 1944), Financial Records (1939-1940), Press Releases (1924-1957), Printed Material (1929-1969), Reports (circa 1937), Speeches (1923-1959), Subject Files (1910-1925), Writings (1925-1962), Miscellany (1923-1972), and Clippings (1916-1972).

B.K. Wheeler's General Correspondence concerns the Senate investigation of the Justice Department (1924-1925), neutrality (1939-1942), and other political issues. Correspondents include B.R. Albin, Franklin D. Roosevelt, Charles Evans Hughes, Barclay Craighead, Lee Metcalf, Mike Mansfield, Ed Craney, Elizabeth Wheeler Colman, and constituents. The Miscellaneous Correspondence consists of letters neither to nor from Wheeler, but concern subjects Wheeler was interested in, such as the Daugherty Investigating Committee regarding Japanese fishing near California (1924), the National Committee on Relations with Latin America (1927), and the Sewell Avery-Montgomery Ward controversy (1944).

The Campaign Materials consist of pamphlets, flyers, campaign letters from the Wheeler for President Club and the Wheeler for Senate Club, transcripts of radio broadcasts, and a booklet--"That Man Wheeler of Montana"--published and circulated by the Wheeler for President Club.

The Press Releases, Printed Material, and Speeches all cover a wide variety of topics, such as the Progressive Party, Robert M. LaFollette, Sr., Wheeler's indictment, remonetization of silver, reorganization of the Supreme Court, neutrality, World War II, America's post-war policy, agricultural problems, and railroads. In addition, the Printed Material includes Senate committee reports and hearings transcripts of investigations of the attorney general and corruption in the Justice Department (1924) and of corruption in the railroad industry (1937). The Reports consist of the text, index, and exhibits of "An Answer to the Testimony in Behalf of the President's Plan" to reorganize the Supreme Court.

The Subject Files contain material on the investigations of J.G. Darden (1910-1920), Harry M. Daugherty (1924), and the U.S. Justice Department (1920-1925). There are also files on the Wheeler Defense Committee and Wheeler's indictment. Wheeler's Writings include many of the same topics found in the printed material, press releases, and speeches. In addition, there are early drafts of Wheeler's autobiography, Yankee from the West.

The Miscellany series contains biographical material on Wheeler, notably Dayton Stoddard's manuscript for a Wheeler biography. Also included are transcripts of an oral interview (1961) and Wheeler's voting record (1923-1946). The Clippings series includes scrapbooks of clippings on the LaFollette-Wheeler campaign (1924), reorganization of the Supreme Court (1937), the Detroit Chapter of the America First Committee (1941), and Yankee from the West.