Answer:
The Red Scare
Step-by-step explanation:
The development of atomic weapons by the US, as well as the eventual usage of them on Japan, led to a massive change in Amerian life. The most prominent of these was when the Soviet Union also figured out how to make atomic bombs using blueprints that Soviet spies stole from the US. When the Soviet Union made and tested its first atomic bomb, this started the Cold War. It led to a fierce arms race between the US and USSR.
Now how did this affect the lives of everyday Americans? During the Cold War, there was a societal phenomenon called the Red Scare, where ordinary citizens would accuse their fellow Americans of being secretly communist and/or having ties to the USSR. This reached its height during an era known as McCarthyism, where Senator James McCarthy went around advocating for this behavior, and even accused many of his fellow Congressmen of being communist.