Harper Lee's novel is semi-biographical as the Finch family resembles her own. Atticus Finch, like her own father, is a liberal-minded attorney in the Jim Crow South in the Depression Era of the 1930's, and Scout is Lee as a girl with Dill being her long-time friend, Truman Capote. In addition, the trial of Tom Robinson is loosely based upon the Scottsboro Trial of 1931 in Northern Alabama, a trial that led to subsequent legal cases dealing with racism and the right to a fair trial.
Maycomb, the country seat, is modeled after Lee's hometown of Monroeville, which is still a sleepy town in rural southern Alabama, an area untouched by the industrialization and immigration of the Northern states. "Reconstruction rule and economic ruin forced the town to grow," Scout narrates; however, she adds, "it grew inward":
New people so rarely settled there, the same families married the same families until the members of the community looked faintly alike.
In other words, there was a certain level of inbreeding. Consequently, as author Thomas Tyron writes, "Narrow lives lead to narrow minds...." and the community of white folks are, for the most part, of one mindset, especially in matters of race, and classes of people.