Manhattan District History (multiple volumes online)General Leslie Groves, head of the Manhattan Engineer District, in late 1944 commissioned a multi-volume history of the Manhattan Project called the Manhattan District History. Prepared by multiple authors under the general editorship of Gavin Hadden, a longtime civil employee of the Army Corps of Engineers, the classified history was "intended to describe, in simple terms, easily understood by the average reader, just what the Manhattan District did, and how, when, and where."
The history is arranged in thirty-six volumes grouped in eight books. Some of the volumes were further divided into stand-alone chapters. Several of the volumes and stand-alone chapters were never security classified. Many of the volumes and chapters were declassified at various times and were available to the public on microfilm. Parts of approximately a third of the volumes remain classified.
