Instead of using existing Defense Department historians , McNamara assigned his close aide and Assistant Secretary of Defense John T. McNaughton to collect the papers . McNaughton died in a plane crash one month after work began in June 1967 , but the project continued under the direction of Defense Department official Leslie H. Gelb . Thirty-six analysts — half of them active-duty military officers , the rest academics and civilian federal employees — worked on the study . The analysts largely used existing files in the Office of the Secretary of Defense . In order to keep the study secret from others , including National Security Advisor Walt W. Rostow , they conducted no interviews or consultations with the armed forces , with the White House , or with other federal agencies
plane crash
Piedmont Airlines Flight 22
Pentagon Papers