For two decades during the Cold War, the United States Army tested chemical weapons on American soldiers at Edgewood Arsenal, a secluded research facility on the Chesapeake Bay. Thousands of men were recruited to volunteer; at the arsenal, they were exposed to chemicals ranging from mustard gas and sarin to LSD and PCP. In the December 17th issue of The New Yorker, Raffi Khatchadourian wrote about Colonel James S. Ketchum, who once headed the clinical studies at Edgewood and has become the program’s most prominent defender. In reporting the piece, Khatchadourian obtained hundreds of Army documents and raw scientific data, along with archival films about the human experiments. Some of the material was provided by doctors who worked at the arsenal; some of it was obtained directly from the government, through Freedom of Information Act requests. (These requests were made with the assistance of Betsy Morais, who works on the magazine’s editorial staff.) We have compiled some of that material here, in an online package called “Secrets of Edgewood.”

Operation Delirium

Beginning in the early nineteen-sixties, Colonel James S. Ketchum spearheaded the Army’s clinical research in psychochemical warfare. This article describes Ketchum’s decadelong pursuit of the perfect non-lethal chemical weapon, and traces Edgewood’s progress from “the place God forgot,” as one soldier called it in 1918, to Vietnam-era conflict, to the research program’s eventual demise.

High Anxiety: LSD in the Cold War

While Ketchum was conducting experiments with a drug called BZ, the arsenal’s chief scientist, Dr. Van Murray Sim, instigated a series of overseas “practical experiments,” in which LSD was tested in enhanced interrogations of unwitting subjects. This online addendum to “Operation Delirium” documents the secret missions to Europe and Asia.

Primary Sources: Operation Delirium

The selected Second World War and Cold War documents featured here—including medical records, technical reports, and firsthand accounts from soldiers who served as test subjects in clinical experiments at Edgewood Arsenal—provide insight into years of Army medical research with chemical weapons.

Video: War of the Mind

Ketchum, a scientist with a propagandist’s eye, documented many of his more ambitious experiments in order to advertise the program within the military. This video, edited and produced by Myles Kane, reveals the inner workings of Ketchum’s 1964 film “Cloud of Confusion.”

Video: Manufacturing Madness

Using Army footage of the clinical research at Edgewood, “Manufacturing Madness” provides a look inside the secret padded wards where experiments with psychochemicals were conducted.

Primary Sources: Sarin in the Sky

When the Army tested sarin, a deadly chemical first developed in Nazi Germany, an accidental casualty in 1952 prompted a detailed study of the agent’s effects. Now, as news circulates of Bashar al-Assad’s plans to use sarin against rebel forces in Syria, this case report shines light on the consequences of a nerve gas that is not widely understood.

Photograph: Stills from “The Longest Weekend”/US Army Chemical Research & Development Laboratories/Courtesy James Ketchum.