Cuban Missile Crisis: A tense confrontation between the United States and Soviet Union in 1962 over the presence of Soviet missiles in Cuba, which brought the world close to nuclear war.
Quarantine: In this context, it refers to JFK's decision to establish a naval blockade around Cuba to prevent further Soviet shipments of weapons.
Assassination: The act of killing someone, often referring to JFK's tragic death in Dallas on November 22, 1963.