Explain what the author's purpose is when she describes Mr. Underwood's participation in the lynch mob scene in To Kill a Mockingbird.
Note Mr.Underwood's participation in the "lynch mob" scene in Chapter 15 and Atticus' revealing comment about him at the beginning of Chapter 16.
As the editor of Maycomb's newspaper, Braxton Bragg Underwood serves as a neutral voice of reason in To Kill a Mockingbird. Underwood rarely leaves his office, and this is one of the reasons he is silently standing guard over Atticus and the jail on the night that the lynch mob arrives. It is also possible that, as the eyes and ears of the town, he, too, has heard the rumor that Tom Robinson will be paid an unexpected visit while Sheriff Heck Tate is on a "snipe hunt." Because most newspapermen attempt to be fair and unbiased, Underwood (named after one of the Confederacy's most reviled generals) probably hoped for a fair trial; in any case, he must have decided that Tom, at the very least, deserved his day in court.
Atticus' comment later that "Braxton... he despises Negroes, won't have one near him," illustrates even more strongly Underwood's desire for justice. His editorial following Tom's death shows no sign of his hatred of African-Americans: He is, first and foremost, a newspaperman who keeps his own personal prejudices out of the story.
Mr. Underwood was the newspaper editor who lived over the newspaper office across from the jail. Many people didn't like him, and he didn't like many people. During the confrontation in front of the jail when Atticus was protecting Tom, Mr. Underwood stood in his window above the newspaper with a rifle or shotgun at the ready. I got the impression that if things turned ugly, he would back up Atticus. He was not one to get involved, but after the mob broke up, Atticus mentioned his thanks to the man in the window. Mr. Underwood acknowledged his thanks. As an editor, he would need to be able to view both sides of an issue without actually getting involved. That is probably what Harper Lee was trying to show. He wasn't really involved, but in good conscience, he couldn't allow mob mentality to break down the fragile, civilized veneer of Maycomb.