How does Harper Lee present prejudice throughout the novel?

Prejudice is a common theme throughout To Kill a Mockingbird. The story is set in the Deep South during the 1930s, a time and a place where racial prejudice was deeply ingrained in society. Harper Lee portrays prejudice in all its ugliness through the words that people speak and the actions they carry out. Examples of the former would include copious uses of the n-word. The near-universal use of this notorious epithet is an indication of just how deeply the roots of prejudice reach in this society.
In Maycomb, prejudiced actions are also disturbingly commonplace. The trial of Tom Robinson—the most blatant example of prejudice in the whole book—is a prime illustration of this. There's no evidence whatsoever to suggest that he's guilty of the rape and assault of Mayella Ewell, but in a society as prejudiced as this, that's considered to be of minor importance. Tom Robinson is "guilty" of nothing more than being a black man accused of raping a white woman. The very fact that he's been accused is sufficient to condemn him in the eyes of most people in Maycomb. If that isn't prejudice, then nothing is.
Harper Lee is also keen to highlight the effect that prejudice has on people—not just its victims, but also those with a prejudiced outlook. In particular, she shows us how prejudice prevents such people from realizing how ridiculous they are. We see this in the scene involving Aunt Alexandra's missionary circle, where the assembled ladies express concern over the spiritual and material welfare of a remote African tribe while at the same time using racial slurs against Maycomb's African American community.
A similar lack of self-awareness is evident when Miss Gates condemns the Nazis for their persecution of the Jews. This is the very same woman who expresses her approval at the wrongful conviction of Tom Robinson, which she believes will serve to keep African Americans "in their place."

Harper Lee presents prejudice throughout the novel by depicting the thoughts and actions of the racist community members of Maycomb. Lee also depicts prejudice by illustrating how negative rumors adversely affect Boo Radley's life. Lee uses specific characters such as Mrs. Dubose, Mrs. Merriweather, and Bob Ewell to depict the prejudice against African Americans in Maycomb. Lee also uses characters like Miss Stephanie Crawford to portray the prejudiced feelings towards Boo Radley. The community member's racist comments and negative attitude towards Atticus also depict their prejudiced beliefs. Lee also portrays how the community's prejudice harms specific individuals. Tom Robinson becomes a victim of racial injustice and the rumors surrounding Boo Radley give him a negative reputation throughout Maycomb. Despite the overwhelming prejudice throughout the community, Atticus remains tolerant and morally upright. He teaches his children to treat others equally which aids in Scout and Jem's moral development.