In Chapter 15 of Harper Lee’s novel To Kill a Mockingbird, Atticus is confronted with the quintessential angry mob, determined to take "justice" into its own hands by breaking Tom Robinson out of jail and lynching him. Such mobs, no matter how driven by self-righteous anger, are often instigated and led by a single individual, or by a small group. Isolating that individual or group, then, is the key to defusing tensions and preventing further trouble. In Lee’s novel, the angry mob is driven by the virulent racism endemic to the American South during the first half of the 20th Century. The mob that gathers in front of the Maycomb jail where Tom is being held are mostly from outside of town. Scout, the novel’s narrator, is thrust into the action when one of the outsiders, a large, burly man unknown to the children, grabs Jem. The young girl responds by kicking the hostile man. As she looks around her, though, she finally sees a familiar face among the mob, Mr. Walter Cunningham, a former client of Atticus’ law practice. Scout calculates, correctly, that if she can make common cause with this one individual, it will help to quell the angry mob that surrounds her and that threatens her father. Calling out to Mr. Cunningham with a friendly greeting, Scout initially feels that her gambit is failing, even when she informs Cunningham that his son is her classmate and that he is a good kid. She also appeals to his association with her father, mentioning “entailments.” As described in the following passage, Scout’s tactics begin to bear fruit:
“Atticus had said it was the polite thing to talk to people about what they were interested in, not about what you were interested in. Mr. Cunningham displayed no interest in his son, so I tackled his entailment once more in a last-ditch effort to make him feel at home. ‘Entailments are bad,’ I was advising him, when I slowly awoke to the fact that I was addressing the entire aggregation. The men were all looking at me, some had their mouths half-open. Atticus had stopped poking at Jem: they were standing together beside Dill. Their attention amounted to fascination.”
Having succeeded in diverted the mob’s attention, Scout has prevailed in defusing the tension. Mr. Cunningham, having been confronted by this small girl, has lost his capacity for violence. Responding suddenly to Scout’s previous request that he give her regards to his son, Mr. Cunningham ends the confrontation with Atticus:
“Atticus said nothing. I looked around and up at Mr. Cunningham, whose face was equally impassive. Then he did a peculiar thing. He squatted down and took me by both shoulders. ‘I’ll tell him you said hey, little lady,’ he said. Then he straightened up and waved a big paw. “Let’s clear out,” he called. ‘Let’s get going, boys.’”
Mr. Cunningham, the one member of the mob who resided within this community, was the apparent leader. By appealing to his sense of decency, Scout caused him to calm down and regain a sense of perspective. She succeeded in humanizing the situation at a time when these hostile, potentially violent intruders were intent on seizing and murdering a man they viewed as an inferior being. Scout diverted their attention away from their mission and towards herself and, in so doing, injected the innocence of a small child into the atmosphere. The key, however, lay in her ability to appeal to Mr. Cunningham’s sense of decency. Once she had accomplished that, he was no longer of a mind to instigate a riot and a murder. Once the leader of the mob had been essentially defused, the rest were content to forget their plans and go on home. Kill the head, and the body will die, as the saying goes. Mr. Cunningham was the head. The rest of the mob was the body. Once he had been contained, the rest were helpless.
The mob broke up due to Scout. She was asking the Cunninghams about there entailment and how Walter was getting along. Saying this, Mr Cunningham becomes guilty and takes the Cunninghams away.