Answer:
Cuban Missile Crisis
Assassination of John F. Kennedy
Vietnam war
Step-by-step explanation:
The Cuban missile alarmed America to the point of starting a world war. Cuba had the Soviet Union building nuclear weapons on Americas backyard, tensions escalated to US bombers preparing to invade Cuba with nuclear weapons.
Assassination of John F. Kennedy, the president was one of the greatest men to have ever lead America. Kennedy funded space exploration until a man was put on the moon. Kennedy stopped the next world war and he still holds the highest approval rating in America.
The Vietnam war is remembered as a loss, waste of young life, unnecessary and brought humiliation to the United States Army from assigning drafts that caused the soldiers stress to costing the nation $1 Trillion in todays money.