During World War II, the Department of the Interior issued a special use permit to conduct intelligence operations at Fort Hunt. Two of the programs conducted here were MIS-X and MIS-Y. The former sought to communicate with prisoners of war in Europe, and delivered to American soldiers escape and evasion kits disguised as humanitarian aid package.
MIS-Y secretly interrogated nearly 4,000 German scientists, officers, and spies. This was the largest Joint Interrogation Center in the county, and many of the interrogators were German-born Jews or refugees from other groups. According to the veterans who served there, interrogations often involved playing chess or other games to glean information from prisoners; when these veterans were honored in 2007, several of them emphasized that violence and torture were not part of the interrogations. Often the presence of prisoners was not reported to the Red Cross for days, which was nevertheless in defiance of the 1929 international treaties which would become the modern Geneva Conventions in 1949.
The historical marker on a flagpole at Fort Hunt is dedicated to the veterans who served there. It lauds the importance of this intelligence work not only in aiding the Allied war effort, but in serving the United States during the Cold War and space race.
The National Park Service maintains Fort Hunt as a public park now and hosts an oral history project collecting stories of people who worked at the secret interrogation site.