In "To Kill a Mockingbird", how does Atticus quietly protest Jim Crow laws even before Tom Robinson's trial?
Atticus protests the Jim Crow laws through his attitude and actions. He is not afraid to go against the code of Maycomb society, and he attempts to teach his children the same sense of social justice. For example, he will not let Scout use the term "nigger". She thinks it's fine because other people in the town use it, but Atticus understands the derogatory nature and the potential harm such a word can do.
The most obvious way Atticus protests the Jim Crow laws is through his relationship with Calpurnia. Although she is his employee, she is not subservient or looked down upon as other people at this time may have looked down on their servants. She is a strong-willed member of the Finch household. In several places, she is described as a mother figure for Scout and Jem. She imparts wisdom, and helps them mature throughout the book. Attics even invites her to stay at their house one stormy night. This level of comfort and equality with black employees was unheard of at the time. When Aunt Alexandria comes to stay, she tries to convince Atticus to fire Calpurnia, precisely because she feels Calpurnia has had too much influence on the children. But Atticus defends Calpurnia's role in their lives, and holds her in the highest respect.