The United States
A secret high level group that was created to examine the problems from the creation of the atomic bomb.
I suggest reading Richard Rhodes book: The Making of the Atomic Bomb.
USA
FDR
Creation of the atomic bomb
Truman
I believe you are referring to Albert Einstein, but he was not allowed to join the Manhattan Project because of his foreign birth. His atomic theories were responsible for the creation of the atomic bomb, but he did not help in its construction and testing.
well, the atomic bomb research was done by Robert oppenheimer. the original creation or idea was from albert Einstein
yes
One was the discovery of Plutonium.
H.G Wells
J. Robert Oppenheimer, while working on the Manhatten Project, directed the creation of the atomic bomb.