It brought about the cold war. The US and the USSR were afraid to do too much against the other because the bomb was a lethal and deliverable weapon. Many films were made about this. You could try finding Dr. Strangelove or How...
It ended WWII or at least the war in the Pacific.
It paved the way for the technology that is used to produce electricity from atomic energy.
It brought about a greater interest in studying blood diseases like Leukemia.