"Atticus Finch is a man of impeccable integrity. Defend this statement using specific details from the novel." I have been working all morning and can not find any specific details to answer the question.
As you read through the novel, you can pick out quotations from episodes that demonstrate that Atticus Finch will never compromise his ideals either to obtain personal advantage or to yield to social pressure. This is most apparent in his decision to defend Tom Robinson, something he knows might not just might him unpopular but would also put him in physical danger from angry white supremacists. There are many scenes in which people try to persuade Atticus to drop his support for Robinson and Atticus refuses.
Finch's talk with Scout before the trial is an excellent example of this. He knows that Robinson will not get a fair trial, but Finch goes ahead with the defense, even knowing the jury is too prejudiced to listen to facts, simply because it is the right thing to do.
When Atticus teaches his children not to hate Mr. Cunningham for becoming part of a mob, he also demonstrates moral integrity, refusing to fall into the easy emotional position of anger and revenge, and standing by a position of fairness and justice even when he himself is at risk.
Another example of Atticus' integrity is the way he refuses to yield to class prejudices, and invites Walter Cunningham into his house and refuses to condemn Boo Radley. Rather than yielding to the social pressure to scapegoat the downtrodden, Atticus always teaches Scout and Jem that they should try to understand other people's perspectives. The specific details you can use to illustrate this are quotations from dialogues between Atticus and his children.