Jem Finch's actual name is Jeremy Atticus Finch, from his fathers name, Atticus Finch.
Jem loves football and hopes to play it at some point in his life, but his dreams are crashed when he breaks his arm. Jem Finch is Scout Finch's brother. He is four years older than Scout. When the book begins, Jem is ten years old. The book ends when he is almost thirteen.
As the events of the book progresses, he matures and puts his childhood behind him, losing innocence and behaving in an adult manner. He is sickened by the bigotry and injustice he witnesses. An example was his reaction to learning that the court found Tom Robinson guilty of raping Mayella Ewell simply because of his skin color.
He broke is arm in the fight with Bob Ewell, and was saved by Boo Radley.
‘His face was streaked with angry tears.’-Chapter 22, after the trial.
‘...I watched the spark of fresh adventure leave his eyes.’-Chapter 8, after Boo Radley put a blanket on Scout.