Harper Lee’s To Kill a Mockingbird illuminates the racism and prejudice that pervaded American society in the 1930s, some twenty or thirty years before the civil rights movement began in earnest.

The story is set in Maycomb, a fictional Southern town where people are resistant to change. Though the inhabitants of this small town necessarily live out their lives in close proximity to one another, a myriad of factors, including race, heritage, and wealth, form a complex social hierarchy within the town. Segregation separates the town along racial lines, but rigid social distinctions govern relationships within Maycomb’s white community as well. The well-to-do may live near and frequently interact with the town’s working-class and impoverished members (as seen in Scout’s classroom), yet the divisions between these groups remain rigid.

It is suggested that this unyielding hierarchy stems from the instinctive desire of individuals in every class to believe that they are superior to others, which creates complex status relationships that extend beyond the traditional socioeconomic and racial sphere. For example, the Cunninghams feel justified in looking down on the Ewells—although they are both poor, white families—because the Cunninghams’ well-known pride and independence garners them greater respect in the town. As Jem observes, 

The thing about it is, our kind of folks don't like the Cunninghams, the Cunninghams don't like the Ewells, and the Ewells hate and despise the colored folks.

Poor, rude, and hostile, the Ewells are despised by most of the town and thus occupy one of the lowest rungs on the social ladder. However, due to the rampant racism in Maycomb, even the Ewells are considered to be socially superior to respectable Black individuals like the Robinsons. The Ewells are aware of this fact and exploit this bias to their advantage in accusing Tom Robinson. Though Bob Ewell is aware of Tom’s innocence, he also knows that as a white man, it is he, not Tom, who will have the town’s support—regardless of how unpopular he is. The hollowness and hypocrisy of Maycomb’s strict social hierarchy ultimately highlights the truth of a key lesson expressed in the novel: “There’s just one kind of folks. Folks.”

Narrated by a young woman recalling her childhood, To Kill a Mockingbird is a bildungsroman, or a coming-of-age story. Through the memories and reflections of an adult Scout, readers follow Scout; her brother, Jem; and their friend Dill as they grow up and learn to navigate the difficulties of coming of age in a changing society. The children are surrounded by conflicting attitudes, particularly with regard to race and class, and must decipher for themselves which ones to adopt as their own. The children don’t undertake this journey completely alone, however; and many of the adults closest to the children—including Atticus, Calpurnia, and Miss Maudie—act as strong moral role models, helping to guide the children toward integrity and away from cynicism, even in the face of terrible injustices.

The book’s title comes from the notion that “it’s a sin to kill a mockingbird,” which is referenced by multiple characters in the book. The underlying explanation of this rule—that it is wrong to harm the innocent—is one of the primary messages of the work. The most clear parallels to the titular mockingbirds are Tom Robinson and Arthur “Boo ” Radley, both of whom, like mockingbirds, are innocents harmed by the harsh ignorance and prejudices of the town. Tom's race makes him an easy scapegoat in a town mired in racism, which Atticus refers to as “Maycomb's usual disease.” In sharp contrast to Bob Ewell, Tom is a kind man who...