The class division in Maycomb is related to racial tension. First of all, there is a connection between race and class. Anyone who was not white was already a member of the lower class. The poor are looked down upon by some, because family connections are considered important in Maycomb. As with racial differences, differences in class usually relate to lack of understanding.
The Cunninghams are an example of a poor family that is still noble. They try to pay their bills and send their children to school. The Ewell family, on the other hand, is not noble. Bob Ewell drinks away his government relief checks and hunts out of season to feed his family while his oldest daughter is left taking care of the kids.
The South, which was still steeped in its agricultural traditions, was hit hard by the Great Depression. Small farmers like Lee's Walter Cunningham Sr. often could not earn enough cash from their crops to cover their mortgages, let alone living expenses. (enotes historical context)
The Robinsons are more like the Cunninghams than the Ewells, but since they are black they are looked down upon by the members of Maycomb’s middle class. It is an example of how race is more of a barrier than class.
Throughout the novel, Lee depicts the differences in social classes as well as the racial divide in the Deep South during the 1930s. Social classes are divided (generally) into three categories throughout the community of Maycomb. The Finch family, along with the other white, educated community members, occupies the upper/middle class of the community. White professionals were respected and lived relatively comfortable lives compared to those in lower classes during the 1930s.
Uneducated white farmers occupy the lower class of Maycomb's society. They struggle to make ends meet during the Great Depression and are represented by the Cunningham family throughout the novel.
The lowest class is occupied by the African Americans. During the Jim Crow era, African Americans were segregated and discriminated against throughout the Deep South. Lee portrays this racial divide by illustrating how African Americans must attend their own church, live at the other end of town, and occupy the balcony during the trial. Lee also depicts how African Americans suffer racial injustice by depicting Tom Robinson's trial.