Answer:
The Black Codes, sometimes called Black Laws, were laws governing the conduct of African Americans (free blacks). The best known of them were passed in 1865 and 1866 by Southern states, after the American Civil War, in order to restrict African Americans' freedom, and to compel them to work for low wages. However, Black Codes existed before the Civil War, and many Northern states had them. In 1832, "in most of the United States, there is a distinction in respect to political privileges, between free white persons and free coloured persons of African blood; and in no part of the country do the latter, in point of fact, participate equally with the whites, in the exercise of civil and political rights."
The treaty of versailles declared Germany guilty of aggression.
Germany was forced to pay 33 billion dollars and many parts of it like Alsace lorraine, coal mine at Saar were given to France.
Moreover it had to supply huge amounts of coal to Belgium and Italy as well.
Its army,navy and ships were reduced.
In short, it had to take over the blame and responsibility of the World War1
Obama's visit was historic considering that he is the first American president to ever visit the country. What is also interesting is that the US bombed Laos in the 70s with over 2 million tons of bombs. During his visit, Obama promised that the US would double its financial aid to the country over the course of the following three years, which was also an interesting part of the visit.