There are a number of characters that show courage after getting into trouble and that persevere despite the high likelihood of failure.
Jem offers the novel's first example of this behavior when he gets his pants caught on a fence in the Radley yard.
When Jem loses his pants in the "raid" on the Radley house, he insists on returning for them during the middle of the night—not so much to avoid the pain of punishment, but because "Atticus ain't ever whipped me since I can remember. I wanta keep it that way."
Atticus, Mrs. Dubose and Tom Robinson also show similar courage.
Tom Robinson takes a chance at being misunderstood when he offers to help Mayella Ewell and refuses payment. This generosity is unorthodox and for this reason opens Tom's motivation to question.
He is an intelligent man and aware that his help is taken for granted and could even be misconstrued. He has the courage to help her anyway...
Despite the chance that his generosity will be misunderstood, Tom continues to help Mayella with chores around her house when no one else will.
The courage shown by Atticus Finch and Mrs. Dubose is given a particular articulation when Atticus explains to Jem and Scout just what Mrs. Dubose was going through at the end of her life. In freeing herself of a morphine addiction, Mrs. Dubose was enacting an ethic of courage that Atticus respects deeply.
Mrs. Dubose behavior, for Atticus, is definitive of courage.
...the true meaning of courage: "it's when you know you're licked before you begin but you see it through no matter what," Atticus tells them...
While Mrs. Dubose overcomes physical demons, Atticus is pitted against the town's social demons. He undertakes a struggle against institutional racism though he understands that he is "licked" before he begins.
These instances of courage are of a special type. Other examples of courage abound in the text, of different types, as Jem attempts to rescue Scout from an attack and Boo Radley successfully achieves this rescue. Miss Maudie courageously accepts the facts when her house burns down. Scout faces down a mob.