It is difficult to generalize the situation of the white population after the Civil War, as it varied across regions and social classes. The North was less affected by the Civil War, and its economy improved in the post-war years. This continued to be focused on manufacturing. The North also received a large influx of immigrants, both from the South and from Europe.
In the South, the situation was different. The war brought enormous disruption to the region, not only in economic terms, but also in terms of social identity. Therefore, the backlash against the black population was stronger, and many of the goals of the war could not be achieved during the Reconstruction period.
B. The Roman Empire traded with Han China because Chinese silk had been found in early Roman cities.
This is of course somewhat of a subjective question, but in general many would believe that the United States should be praised for the military strategy of "Europe First".
The War Hawks encouraged American sentiments for nationalism for their country.
Martin Luther King's famous speech "I Have a Dream" deals with racism and segregation of people of color. He says in his speech that he wishes for a world where those things don't exist, and where every human is free and shares equal rights as everyone else, regardless of religion, gender, skin color, or sexual preferences. Hope this helps!
