To start the us policy of containment was made because of the fear of communism spreading. An example of containment is when Russia sent nuclear missiles to cuba which in turn created the Cuban missile crisis, the us then set up a "quarantine" around northern cuba to protect the us. Russia later took the missiles back and tensions fell. Another example is the situation in Berlin, West Berlin was communist, East Berlin was democratic, the communist vision eventually fell with the Berlin wall which promoted democracy. The us also gave billons of dollars to Europe to promote democratic growth. The quarantine is basically against communism and promoting a democratic style.
Chinese and Irish Immigrants, and African Americans
