The Floyd Millard Riddick Papers, 1909 to 2000, (bulk 1950-1983), consist of correspondence, writings and speeches, printed material, senate documents, photographs, and organizational papers documenting Riddick's career as the Assistant Parliamentarian, Parliamentarian, and Parliamentarian Emeritus of the United States Senate. The Correspondence Series includes correspondence to and from senators, presidents, and other political figures concerning the rules and procedures of the United States Senate.

Between 1937 and 1947, some of the letters in the Correspondence Series relate to social conditions and political events in Germany before, during, and after World War II. Riddick, who resided in Germany during 1937 and 1938, maintained correspondence with friends and associates during this period. The letters provide insight into the ways in which the rise of National Socialism and the War affected this group of friends. Among the letters from Riddick's acquaintances in Germany is one giving an account of Krystallnacht; several from a young Jewish woman who wanted Riddick to assist her in obtaining admission to the United States as a student; and a few from a man who became a German soldier. A scrapbook and Riddick's personal diary (Miscellaneous Series) add further commentary on pre-war Germany.

Early in his senatorial career, Riddick was actively involved and interested in the organization and procedures guiding Congress. He began publishing books on parliamentary procedure in 1941, and by his retirement in 1974 he was honored for his dedication to congressional procedures and named Parliamentarian Emeritus. Considered to be the authority on parliamentary procedure, Riddick continues to edit and republish The Writings and Speeches Series consists primarily of notes, drafts, proofs, and copies of Riddick's published works and of notes for speeches made by Riddick. The Senate Activities Series contains material pertaining to Senate committees and task forces of which Riddick was a member. Agendas, pamphlets, and correspondence pertaining to other organizations of which Riddick was a member comprise the Organizational Records Series. This series includes papers relating to practicums on parliamentary issues held by Riddick for members of the American Institute of Parliamentarians.

Photographs of Riddick, his acquaintances, and his associates, many of whom were prominent political figures, make up the Picture Series. The Printed Material Series contains clippings, pamphlets, programs, and congressional documents pertaining to or of interest to Riddick. The Miscellaneous Papers Series includes an assortment of materials including awards Riddick received, documents relating to his trip to Germany, a diary (with transcription), scrapbooks kept by Riddick, and retirement tributes.

The addition (2007-0165) (50 items; 0.9 lin. ft.; 1928-2000) consists of Riddick's publications about parliamentary procedure; obituaries and other remembrances addressed to Riddick's wife upon his death; his high school diploma; and several VHS tapes, audiocassettes, and a mini-VHS cassette containing interviews and presentations by Riddick about his role as the Senate Parliamentarian.

The addition (2008-0179) (100 items; 0.6 lin. ft.; 1933-1992) contains publications, academic materials, clippings, correspondence, and miscellaneous materials, including a copy of the Senate Resolution 443 that declared Riddick to be the Parliamentarian Emeritus of the U.S. Senate. This addition has been interfiled with Accession (2007-0165).