In To Kill a Mockingbird, Lee tells us that there are different kinds of conflict, but larger conflicts affect smaller ones.
Although the overarching conflict in the book is the character vs. society conflict with racism, there are smaller character vs. character and character vs. self conflicts that derive from it.
The main conflict in the story is the problems brought to Maycomb when the town has to face the realities of its own racism during Tom Robinson’s trial. Robinson is clearly innocent, and the crime never took place, but his trial is a polarizing event. The very untrustworthy Ewells have accused him, and since he is a black man their word has to be taken over his.
The state has not produced one iota of medical evidence to the effect that the crime Tom Robinson is charged with ever took place. It has relied instead upon the testimony of two witnesses whose evidence has ... been called into serious question on cross-examination. (ch 20)
Yet despite this evidence, Robinson is convicted. The effects of the trial are seen in Maycomb long before it even begins. Scout, Atticus Finch’s young daughter, learns what racism really means when children and adults start insulting her because her father is defending him.
"Then why did Cecil say you defended niggers? He made it sound like you were runnin' a still." (ch 10)
Scout has been raised to treat everyone with respect, regardless of skin color. She really does not understand what Cecil, Mrs. Dubose, Cousin Frances and the others have against her father defending a black man. This causes an internal conflict for Scout, because she does not know what to do. She does not want to disappoint her father by fighting, but she does not want to allow them to insult him either.
Thus, To Kill a Mockingbird not only demonstrates the impact on conflict on a small town, it also shows us the impact on a small girl trying to understand how the world works.