In what ways is the narrative about Atticus's fighting racism and prejudice in To Kill a Mockingbird?

Atticus Finch, an aberration in the South of the 1930's, practices with fairness to all in a town firmly entrenched in Jim Crow, and he tries to prevent his children from contracting "Maycomb's usual disease" through his teachings, actions, and speech.

Harper Lee's novel, To Kill a Mockingbird, depicts a Southern town in which little change has occurred in decades. Then, when a lonely "white trash" girl is caught breaking "a rigid and time-honored code" of the town, she attempts to put the evidence of her offense "away from her" by making false accusations against the kind-hearted black man who walks past her yard on his way home and sometimes helps her with tasks. When her father catches her kissing him, he beats her, but still charges Tom with rape in order to cover up both their actions.
After Atticus is assigned the task of defending this black man named Tom Robinson, he becomes the recipient of many invectives, even from members of his extended family. At holiday time, Scout is told by her cousin Francis, 

"Grandma says it's bad enough he [Atticus] lets you all run wild, but now he's turned out a nigger-lover we'll never be able to walk the streets of Maycomb agin. He's ruinin' the family, that's what he's doin'." 

Mrs. Dubose, a neighbor, accuses Atticus of being no better than the "n****s and "trash he works for!" Further, she tells Scout that she will only be waiting on tables when she grows up, then adds,

"Not only a Finch waiting on tables but one in the courthouse lawing for n*****s."

Despite all the negative comments about him, and the challenge of the mob who have come for Tom at the jailhouse before the trial, Atticus has the integrity to do his job. He challenges the men by sitting before the jailhouse door, adamant that no lynch mob may have Tom. Moreover, Atticus firmly believes that a fair trial is for everyone, not just white people. In his closing arguments at Tom's trial, he speaks to the jury, reminding them that in a court of law, "all men are created equal."

Although Atticus has lost in the trial, there are those who respect him, such as Miss Maudie, who tells Alexandra, his sister, that Atticus has been paid a high tribute because he was entrusted with the task "to do right" as he has done for Tom.