A Favor for FDR

It was Germany, not America, which first split the atom. The US didn't have a clue until Einstein warned the White House some years after the Nazi research began. The man in charge of German nuclear research was Werner Heisenberg, a founder of modern quantum physics. His American counterpart, Robert Oppenheimer, was a scientific novice compared to Heisenberg.
However, in the end, the difference between success and failure turned on the financial and political backing the two research teams received. The Americans were completely supported by their government, with millions of dollars spent to develop the national capabilities in nuclear science, while the German scientists suffered from lack of governmental interest, paltry funding and their own lack of vision.
Even with these handicaps, it is historically amazing how far the German effort progressed and many of their findings were instrumental in the success of the American bombs dropped on Hiroshima and Nagasaki.