At this time colonies were viewed as a major factor in determining a nations power internationally and also an engine for economic growth in a mercantilist system. Therefore, arguments in favor of U.S. Imperialism would have been fueled by the power struggle with European nations to exert global influence and dominance. Another major factor that individuals would have argued for was that colonies would have provided new markets and sources for raw materials for the growing US economy. In the end the U.S. did not become a major imperial power which most likely served the nation's power and reputation in the long run.
Divisions within the christian religion were initiated by Martin Luther during the 1500s, since it was Luther who believed that the Catholic Church had become corrupt--both morally and financially. He began the religion of Protestantism.
During WWll, with white men fighting overseas, African Americans were able to get better job opportunities, and a new law passed saying that blacks and whites had to be in integrated units in the army. But, when the war ended and black soldiers returned to America they weren't greeted with a hero's welcome and instead were treated like all other blacks- they were forced to be segregated. This change from almost equality to none at all really fired up the Civil Rights Movement in the 1950's and 1960's.