The papers consist of correspondence, political memoranda, campaign literature, and printed matter documenting Kenneth Simpson's career as chairman of the Republican County Committee in New York (1935-1940). The papers also include case and client files from Simpson's legal practice. The papers highlight Simpson's support for Fiorello LaGuardia in the 1936 New York mayoral campaign, his opposition to Thomas E. Dewey's candidacy for presidential nomination in 1940, and his own successful campaign for election to the United States House of Representatives from the Seventeenth Congressional District of New York in 1940.