In a speech about Atticus Finch, there are a number of events and qualities relating to his character that will be pertinent. Organizing your speech around two or three traits found in Atticus may be a way to focus your work.
Courage and dedication to a sense of justice are two of the strongest traits in this character. Demonstrated in his behavior in defense of Tom Robinson, each of these traits is borne out by action and dialogue in the text.
In talking about Mrs. Dubose, Atticus articulates his respect for acts of courage:
"it's when you know you're licked before you begin but you see it through no matter what..."
In defending Tom Robinson, Atticus Finch risks his personal safety and his reputation.
When he takes on Tom Robinson’s case, he is determined to do all he can to defend him, even though he knows Tom’s case is all but hopeless...
From the night before the trial when Atticus waits for the lynch mob until the day of Tom Robinson's death, Atticus does not waver in his dedication to the cause of justice. He acts resolutely to see that Tom is protected and that he has a fair trial.
Regarding the scene outside the jail house, it should be made clear that the lynch mob is not a Ku Klux Klan group, but a gaggle of local men out to see "mob justice" done. This is not an organized group. It is a haphazard, half-drunk assortment of country-folk who have riled themselves up to do what is expected of them.