Imogen has left the big city for the hometown she grew up in. She was now back to a place where people knew her. This is because when growing up Imogen had interaction with other people who can observe her and form opinions about her. What it means to know someone is to spend time with them and get to know their idiosyncrasies.
John Brown was an American abolitionist who advocated insurrection as a means to end slavery in the United States. For his activities outside the law, Brown was accused of treason against the Commonwealth of Virginia, found guilty and hanged.
Prior to his death and after his sentencing, a large number of prominent figures raised money and wrote speeches in his defense. One of this people was Ralph Waldo Emerson. Emerson presented Brown as a common, everyday man who had strong ideals and felt compelled to act upon them. This was intended to present Brown as an admirable man and to invoke sympathy among the people by identifying themselves with him.
A paragraph with its topic sentence last would be called an inverted triangle. The point (being the topic), The base (being anything backing up the topic).
