Correspondence, diaries, speeches, articles, transcripts of tape recordings, research notes, notebooks, financial and legal papers, bioliographical file, and newspaper clippings relating to Hooper's part in the planning and growth of radio communications in government service, his work in building the shore-detection radio finder system for the Navy, his design and construction of many of the Navy's high-power radio stations, his delegacy to national and international radio conferences in the 1920s and 1930s, and his role in persuading the U.S. government to help establish the Radio Corporation of America. Other subjects include long-life receiving and transmitting tubes, high-power vacuum-tubes, simultaneous multiwave communications systems, remote control radio operational techniques, depth finders, sound-oscillated radio systems, the application of long distance radio techniques to aircraft, submarine sound detection systems, and radio-controlled target practice experiments. Correspondents include William S. Benson, Mark L. Bristol, Richard E. Byrd, Jr., Royal S. Copeland, Josephus Daniels, John Hays Hammond, Jr., James G. Harbord, Hiram W. Johnson, Emory S. Land, Thomas A. Marshall, Elihu Root, Daniel C. Roper, David Sarnoff, and Owen D. Young.