why did Atticus give Scout for the fact that he was defending a black man and how did she feel?

As Atticus has explained to Scout many times about this, He is doing this becasue he values equailty and justice. He believes that everyone is equal and therefore just because Tom Robinson is black, doesn't mean that he should not defend him. He says to Scout many times, if he did not defend this man, he could never tell Jem or her (Scout) not to do something.