There are three references to racism in chapter 1 of To Kill a Mockingbird. The first reference comes when Scout is talking about her family's ancestor Simon Finch, who,
having forgotten his teacher’s dictum on the possession of human chattels, bought three slaves and with their aid established a homestead on the banks of the Alabama River.
This homestead is, at the time of the story, occupied by Atticus's sister, Alexandra. This brief, seemingly insignificant allusion to Simon Finch's possession of slaves is a reminder that slavery at this time was ubiquitous. Even the life of a liberal person like Atticus has racism in its ancestral roots.
The second reference to racism is when Scout is describing Boo Radley's house. She describes it as a frightening place, a place which the people of Maycomb County would associate with crime and wrongdoing. Scout explains that
A Negro would not pass the Radley Place at night, he would cut across to the sidewalk opposite and whistle as he walked.
A black person...
(The entire section contains 3 answers and 710 words.)