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.
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.
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.