<span>The Declaration of Independence</span>
Answer:
The correct answer is B, <em>Republicans in Congress did not trust white southerners to adopt reforms giving rights to freed slaves</em>.
Explanation:
During this period Congress passed laws in order to reintegrate the country and to enforce what had been fought for in the Civil War, that is, the end of slavery.
After seeing that white southerners were getting their lands back and they were reorganizing their government without making it very differently from before the war, Republicans in Congress decided to enforce the Civil Rights Bill.
For the Bill to be put into practice in the south, Congress divided the South into military districts whose governments would be under martial law until black people's civil liberties were ensured. That meant that black people should be present in the government to ensure African-Americans wouldn't have basic rights denied.
Because it offers the historian an objective snapshot of the public sentiment of the time, which the cartoonist (should be) distilling for their readers, according to their feelings, for mass appeal. I say objective as it is usually very easy to decipher their subjective viewpoint according to the publication. The value of this is that it is tapping into how the masses 'feel' rather than how subjective facts can be built to form historical opinion. It becomes especially valuable prior to this century, when public sentiment is harder to garner as we were less technologically advanced.