I was wondering what the Atomic Energy Commission is/was, and if they were the precursor to the DOE? Or, if they merged, perhaps? …assuming there is no Atomic Energy Commision today(?) - Jinx 
The AEC was the original agency established to assume the responsibility for the facilities and expertise left at the end of WWII. The Manhattan Project was the war time agency responsible for the research and production of the atomic bobmbs that braought an end to the war.
There were IIRC two other names, mnemonics, inbetween the AEC and the DOE.
Vanevar Bush wrote a book in the late 40’s with a great deal of information about the Manhattan project. Check you public library/
“The AEC was dissolved in 1974 and its responsibilities transferred to the Energy Research and Development Administration (these functions are now under the Department of Energy) and the Nuclear Regulatory Commission.”