In 1930s Maycomb, a small town in Alabama, Calpurnia is the black nanny, cook and mother figure to the prosperous white Finch family. In some respects we know very little about her, not even her surname, but this socially inferior servant plays a vital role in the novel as Harper Lee uses her to embody and illustrate many of the themes running through her book: racism, inequality, injustice, class, the importance of family, education and courage. Through Calpurnia we understand what life in the South was like in those segregated times. She provides the voice of morality and humanity in a world with very little of either.
Maycomb is a "tired old town" with "nowhere to go and nothing to buy" in the eyes of the eight year old narrator, Scout. At the start of the novel she does not see the deep inequalities and prejudices that divide it. Her first taste of racism comes at Calpurnia’s all-black First Purchase Church when Lula, a parishioner, objects to the presence of White children saying they have their “own church.” Calpurnia’s response is the essence of pure morality: “It’s the same God, ain’t it?” Here we have a Black woman, the bottom of the social ladder, defending children who come from the White community that has inflicted so much injustice on Calpurnia’s people. Harper Lee is making a strong point that racism and prejudice are morally indefensible no matter whether it is practiced by Blacks or Whites and that Calpurnia’s personal morality will not allow her to stand by while her “comp’ny” is insulted. Most Whites in Alabama in the 1930s would not have behaved with the grace exhibited by this servant woman.
In Maycomb, the class hierarchies were rigid. White families like the Finches were at the top of the ladder while Blacks like Calpurnia were at the bottom automatically, even below white trash like the Ewells and Cunninghams. Calpurnia is poor and like Walter Cunningham cannot afford to eat syrup ever...