What are the unwritten rules about race that Mr. Gilmer attempts to get Tom to break? Does he succeed? What parts of Tom’s testimony might offend...

The trial of Tom Robinson is modeled after the trial of the Scottsboro Boys in Northern Alabama in 1931. During this trial, two white women accused the black men with whom they had been riding in a train car of raping them.  

In the 1930s, Jim Crow Laws affected every aspect of life for black Alabamans: black people faced segregation and anti-miscegenation laws (laws that prohibit interracial marriage and interracial sexual relations). In fact,...

The trial of Tom Robinson is modeled after the trial of the Scottsboro Boys in Northern Alabama in 1931. During this trial, two white women accused the black men with whom they had been riding in a train car of raping them.  

In the 1930s, Jim Crow Laws affected every aspect of life for black Alabamans: black people faced segregation and anti-miscegenation laws (laws that prohibit interracial marriage and interracial sexual relations). In fact, these laws were not ruled unconstitutional until 1967 by the US Supreme Court in Loving v. Virginia).

While Tom is on the witness stand, he makes every effort to choose his words carefully because he is aware of the prejudices of the time and the disadvantages he has. However, Mr. Gilmer, the prosecuting attorney, makes equal efforts to trick Tom, suggesting that Tom had his "eye on her [Mayella] a long time" and inquiring why Tom, who was purportedly busy with his own work, would take the time to help Mayella.

"Tried to help her, I says."
"You're a mighty good fellow, it seems--did all this for not one penny?"
"Yes, suh. I felt right sorry for her, she seemed to try more'n the rest of em--"
"You felt sorry for her, you felt sorry for her?" Mr. Gilmer seemed ready to rise to the ceiling.

Mr. Gilmer insinuates that Tom felt superior to Mayella, suggesting that he, "a Negro field hand," expresses pity for a white woman.

Further in the questioning, Mr. Gilmer asks Tom,

"She says she asked you to bust up a chiffarobe, is that right?"
"No, suh, it ain't."
"Then you say she's lying, boy?"
....
"I don't say she's lyin', Mr. Gilmer, I say she's mistaken in her mind."

Tom does not dare accuse Mayella of lying. Doing so would suggest to the prejudiced jury that Tom has overstepped his place in making any accusation against a white person.