Correspondence, subject files, research materials, and miscellany relating primarily to Hagedorn's biographies of Leonard Wood and William Boyce Thompson. Original materials document Thompson's role in relief work in Russia following the Russian Revolution and in securing diplomatic recognition for the Soviet Union. Includes material on Hagedorn's activities relating to loyalty concerns during World War I especially in relation to his fellow German Americans and the Vigilantes, an organization composed chiefly of patriotic artists and authors.

Correspondents include Charles Fanning Ayer, Newton Diehl Baker, Bernard M. Baruch, Albert Ridgely Brunker, Grenville Clark, George B. Cortelyou, Harvey Cushing, Johnson Hagood, James G. Harbord, Harry S. Howland, Cornelius Kelleher, Frank Ross McCoy, Arthur W. Page, Raymond Robins, Elihu Root, Frank Maximilian Steinhart, Henry L . Stimson, Gertrude Hickman Thompson, William Boyce Thompson, S.M. Williams, and Louisa A. Wood.