On August 15, 1947, the Manhattan Engineering District was formally abolished, although the Manhattan Project ceased to exist on December 31, 1946, with the handover to the U.S. Atomic Energy Commission effective January 1, 1947.
Manhattan Engineering District plaque located in Oak Ridge, TN
The Manhattan Engineering District was created August 13, 1942, and was initially headquartered at 270 Broadway, New York, which was the home to the North Atlantic Division of the U.S. Army Corps of Engineers. Much of the early activities, purchase, and storage of uranium occurred in New York City.
Tower 270 viewed east from Chambers Street with the Tweed Courthouse in the foreground.
The headquarters was eventually moved to Oak Ridge, TN. The project retained the Manhattan Project name, even though the “district” included the entire United States.
The International Friendship Bell in Oak Ridge, Tennessee, is an 8000 pound bronze bell symbolizing the peace and friendship shared by Japan and Oak Ridge. Designed by Oak Ridge artist Suzanna Harris and cast by a family foundry in Kyoto, Japan, the relief panels of the International Friendship Bell represent images of Tennessee and Japan. Additional panels list the dates of Pearl Harbor, V-J Day, and the dates of the atomic bombs dropped on Hiroshima and Nagasaki.
In the Truman Presidential Library in Independence, Missouri, is a short, handwritten reply to Secretary of War, Henry Stimson. In effect, it was the authorization to drop the atomic bomb on Hiroshima.
Sec War Reply to your 41011 suggestions approved Release when ready but not sooner than August 2 HST
On July 30, 1945, Stimson sent an urgent, top secret message (No. WAR 41011) to Truman requesting approval of a statement announcing the use of the atomic bomb for release. A draft of the statement had been prepared previously, but with the Potsdam Declaration and the results of the Trinity test, the final draft and approval was needed.
Conference table at the Potsdam Conference (Harry S. Truman Library, Accession #80-133)
When the Japanese response to the Potsdam Declaration, Mokusatsu, was interpreted by the Allied command as a rejection of unconditional surrender, the machinations to carry out the atomic bombings of Hiroshima and Nagasaki began.
No known written record exists in which Harry Truman explicitly ordered the use of atomic bombs against Japan. The final puzzle piece needed by Stimson for the Manhattan Project was the public announcement by Truman.
Truman wrote his reply on the back of Stimson’s message.
This handwritten order to Stimson, authorizing the release of a public statement, in effect is the closest document to such an order. Thus, “release when ready” for the public statement served as the final authorization.
Truman Library Institute: The Potsdam Conference, 75 Years Later (Webinar; 1 hour lecture)
