The collection contains correspondence and technical reports, and notes Middleton prepared as a consultant for private companies and organizations and government agencies, including the United States Department of Commerce, the United States Office of Naval Research, Naval Underwater Systems Center, the Institute for Defense Analyses, the Rand Company, Raytheon Company, and Lincoln Laboratory at the Massachusetts Institute of Technology on projects including undersea warfare, military communication, and statistical communication theory. There are also correspondence, memoranda, and reports documenting his activities as a member of various boards for the Naval Research Advisory Committee. Also includes professional correspondence, and course notes for physics classes Middleton taught at Harvard University, 1952-1954. Reprints of Middleton's writings and copies of lectures record his work on maritime reverberation, low density noise, signal communication measurement, and physics and its applications to communications technologies.