Harper Lee's childhood was the 1930s+40s. She was influenced by history of slavery in Southern States of the United States that ended with the American Civil War (1861-1865).
Set in 1933-1935 but civil war strongly in minds of the characters.
The south was mainly an agricultural society - produced cotton, tabacco, hemp and sugar on plantations with black slaves.
The north was more urban/industrialised. As time passed Northerners became more and more unwilling to condone what they felt to be the evil slavery in the south.
Southerners argued that the black race was inferior and imported Africans were lucky to be American slaves because their slavery brought them in contact with the Christian Religion.
Southern whites referred to the black race as ignorant, simple minded, lazy, irresponsible and in need of firm guidence from White People. This can be seen in the novel.
After the civil war, the north defeated the south and African American Slaves (called Negroes at the time) were freed. This made the economy worse off as more labour was needed for the new advanced machinery.
Negroes, while no longer slaved, had no/little access to voting, education and employment. The Great Depression in 1929, saw a collapse in the US economy. The rural south was worse affected. White farmers were left bankrupt and competing for a living with landless African Americans. (shown in the novel - The Cunninghams)
In late 1929 the economic prosperity of the 1920s came to an end with the Wall Street Crash followed by the Great Depression. The economic boom of the 1920s rested on a fragile foundation; there was such an unequal distribution of income between the rich and the poor that when things started to falter, there were not enough people to buy goods and services to keep the economy in a healthy state.
People lost jobs, marriages broke down, banks failed, people became homeless, businesses folded, birth rates fell, people got depressed and many people went hungry.
Racial discrimination and prejudice were still…