When was the atomic bomb developed by the US and USSR?

Actually the Germans were on track to build the first atom bomb until many key scientists defected to the US/Great Britain. That enabled the US to create the first bomb and drop it in 1945 which led to the end of WW2.

Answer

The Nazis were nowhere near developing an atomic bomb, the "defecting" scientists mentioned above having left Germany well before WWII. Several were of course, Jews. The Manhattan Project was a joint Allied effort with scientists from many countries apart from the US including Britain, Germany, Hungary and Italy. A German, Klaus Fuchs, was a spy for the Russians which how they so quickly developed their own bomb (and why Stalin wasn't as surprised as he should have been when the Allies used their three bombs).