Racism is a central theme in Harper Lee's To Kill a Mockingbird, depicted through the social dynamics of Maycomb, Alabama. The novel explores the deeply ingrained racial prejudices and injustices that permeate the town, affecting the lives of its characters. Through the trial of Tom Robinson, a black man falsely accused of raping a white woman, and the Finch family's interactions with the community, Lee examines the destructive nature of racism and its impact on individuals and society.

One of the most poignant examples of racism in the novel is the trial of Tom Robinson. Despite clear evidence of his innocence, Tom is convicted due to the color of his skin. This miscarriage of justice highlights the racial bias present in the legal system and the community's unwillingness to see beyond their prejudices. Atticus Finch, who defends Tom, embodies moral courage by standing up against the town's racist attitudes, even though he knows he is unlikely to win. His actions demonstrate the importance of fighting for justice, regardless of the odds.

Racism is also symbolized through the character of Mrs. Dubose, who represents the deep-seated intolerance in Maycomb. Her derogatory remarks about Atticus defending Tom Robinson reflect the town's pervasive racist attitudes. Jem's reaction to her comments, where he destroys her camellias, signifies his frustration and anger towards the injustice he witnesses. Atticus uses this incident to teach his children about true courage, which involves standing up for what is right, even when faced with certain defeat.

The novel further explores racism through the contrasting experiences of its characters. While Atticus is respected for his integrity, he faces criticism for defending a black man. This dichotomy illustrates the societal pressures and prejudices that influence behavior and attitudes. The Finch family's history, with its roots in slave-owning, juxtaposes Atticus's progressive views, emphasizing the potential for change and moral growth.

Lee also uses the innocence of Scout and Jem to highlight the irrationality of racism. As they witness the trial and its aftermath, the children grapple with the harsh realities of racial injustice. Their journey from innocence to understanding mirrors the novel's message that empathy and moral integrity are crucial in challenging societal prejudices. By the end of the novel, Scout learns to apply Atticus's lesson of understanding others by "walking in their shoes," recognizing the humanity in everyone, regardless of race.