Atticus explains what Tom Robinson did by saying that since he was black he had no choice but to run or be killed for a crime he did not commit.
To protect tom from the mob!
Atticus stood guard at the jail so that the local people would not lynch the prisoner that was inside. Atticus felt he needed a proper trial, which did take place, and the man was found innocent.
Atticus knows Tom Robinson is coming back to the Maycomb jail because he received a tip from Heck Tate, the sheriff, that a mob might try to harm Tom. Therefore, Atticus decides to sit by Tom in an attempt to protect him.
are you referring to when the mob approaches Atticus at the county jail? If so, it's because they have come to lynch Tom Robinson, who is in the jail. I believe Atticus suspected this, and decided to go sit in front of the jail to protect Tom.
The Children finds Atticus in front of the maycomb jail.
Atticus is waiting at the jail to protect Tom Robinson from a lynch mob that wants to take vigilante action against him. Atticus shows his courageous and principled character by standing up for what is right in the face of a hostile crowd.
Atticus is worried that Tom is going to be lynched. He sits in front of the jail and a group of men shows up intending to do just that. Scout intervenes and inadvertently causes the men to disband before doing any violence.
Tom is in the Maycomb County Jail during the time that Atticus faces the mob downtown.
Atticus sits by the jailhouse to protect Tom Robinson from a lynching mob. He knows the mob is coming to harm Tom, so he positions himself there to prevent any violence from happening. It showcases Atticus's commitment to justice and doing what is right, even in the face of danger.
Judge Taylor assigns Atticus to defend Tom Robinson.
Jem goes with Atticus to tell Tom Robinson is dead
Atticus' witnesses in the trial of Tom Robinson were Sheriff Heck Tate, Bob Ewell, Mayella Ewell, Tom Robinson, and Atticus himself. Each witness provided their testimony to support their side of the case.