6 Aug 45 . . . Little Boy is dropped on Hiroshima.

9 Aug 45 . . . Fat Man is dropped on Nagasaki.

21 Mar 46 . . . Continental Air Forces is re-designated the Strategic Air Command (SAC). SAC is initially headquartered at Andrews Air Force Base then later is moved to Offutt Air Force Base in November 1948.

14 Jun 46 . . . U.S. presents the Baruch Plan, which calls for placing all atomic resources of the world, including the U.S. arsenal, under the ownership or control of an independent international authority. Soviet objections over verification measures deadlock negotiations.

20 July 46 . . . Atomic Energy Act of 1946, which transfers military control of nuclear weapons development activities to civilian Atomic Energy Commission (ACE), passes Congress.

1947 . . . National Security Act of 1947 sets policy concerning the military’s access to classified nuclear information and the control of atomic matters by civilians.

1947 . . . Mound Plant, responsible for explosive components of nuclear weapons, is established in Ohio. Y-12 Plant (Oak Ridge), responsible for nuclear explosive assembly, is established in Tennessee.

1 Jan 47 . . . Armed Forces Special Weapons Project (AFSWP) is established to assume responsibility for all military service functions of Manhattan Project. The services are authorized to participate in weapons development in coordination with AEC.

17 Jan 47 . . . Secretaries of War and Navy approve Military Liaison Committee (MLC) Charter, establishing membership at six -- three members each from the Navy and Army.

1948 . . . Z-Division's growth prompts its designation as Sandia Laboratory, a separate branch of Los Alamos.

1948 . . . Kansas City Plant, responsible for fuzing and firing sub-assemblies, is established in Missouri.

1948 . . . B4 nuclear warhead is fielded. This is the first atomic warhead to be produced as a weapon and not as a laboratory device.

26 Mar 48 . . . Revisions to the MLC Charter make the chairmanship a SecDef appointed position and membership composed of delegates from each military department.

Apr-May 48 . . . AEC is directed to build Atomic Bomb Stockpile.

16 Sep 48 . . . President Truman signs NSC-30, “United States Policy on Atomic Warfare,” which states that “the decision as to the employment of atomic weapons in the event of war is to be made by the Chief Executive.”

Mid-1949 . . . Nuclear capable B-29s are deployed to the U.K.

4 Apr 49 . . . North Atlantic Treaty Organization (NATO) is established.

May 49 . . . MLC Chairman is made a presidential appointment.

29 Aug 49 . . . The Soviet Union explodes its first atomic weapon, JOE-1, which has a yield of 22 kilotons.