The US was the 'city upon a hill': Using early Puritan ideology abolitionists saw the US as a beacon of equality and freedom which slavery spit in the face of.
The US had been a model for political philosophy and an experiment which was mostly a success but slavery was a flaw. Abolitionists believed we could not be a beacon of freedom with the system in place. The US government refused to deal with the issue and compromises furthered the practice instead of limiting or eliminating it.
It was Theodore Geiger the author of this statement. By this, he meant the Marshall Plan advanced both American and European economies.
The Marshall Plan was a United States' plan to help Western Europe to recover from the destruction caused by World War II, thus "doing well by doing good". The financial aid the US sent to Western Europe was rewarded with increased economical relationships with European countries and with the spreading of American culture in Europe which helped the US to sort of keeping it as an influence zone.
Answer:
I believe it is the last one because I learned about this in seventh grade and the mayans were actually one of the first civilizations to create a 360-day year. forgive me if im wrong