Henry C. Clausen

Henry Christian Clausen (30 June 1905 – 4 December 1992) was the author of the Clausen Report, an 800-page report on the Army Board's Pearl Harbor Investigation. He traveled over 55,000 miles over seven months in 1945, and interviewed nearly a hundred personnel, Army, Navy, British and civilian, as a Special Investigator for the Secretary of War Henry L. Stimson carrying out an investigation ordered by Congress of the Secretary of War.

Source: Henry Clausen on Wikipedia.