Rural Mississippi during the 1930’s had a state segregated society in which whites still saw blacks as lesser human beings.
During that time there were almost 2 different worlds: the black and the white world. Friction between these two worlds happened on a daily basis, the outcome almost always favoring white people.
While the farmlife was more independent and free of segregation (if you owned land), the cities and their institutions heavily discriminated against black people (Jim Crow laws).
In the story we see this with the characters being very stressed while in the city.
Mary Logan having to wait for all the white customers to be spoken to first while she has an appointment at the bank shows how even institutions were racist. The Shop in Strawberry also serves whites before blacks, even if they came in later. Another example of the Jim Crow laws in the book is the bus that drives the white children to school while black children have to walk all the way to school on foot.
Cassies life is seperated into two different worlds.
The black world is made up of the Logan farm, the church and the school for black children, while the white world consists of the cities, the shops and institutions.
Especially white institutions are far superior to black ones, the school for white children even offers a bus to pick the children up and bring them back home.
In this setting the reader learns about the injustice experienced by Cassie and the other black kids. While the school Cassie attends (ironically teaches it’s students about racism while being a great example of racism itself) is the only negative part of the black world, Cassie has to sometimes cross the line into the white world in order to survive. There is no bank for black people or black shop owners who can compete with their white counterparts, thus making black people dependant of the white world.
And everytime they cross the line into the white world there is friction and conflict for example when Cassie wants to buy goods in a shop in Strawberry and gets thrown out unfairly. While the white shops are in nice buildings in the centre of town, the black traders have to set up their shaby market in the outer skirts of the city.
This shows the division of black and white areas inside the city which is heavily favoring white people.