The characters in the text vary greatly, but the majority of the main characters are all connected through John Singer. He is a deaf-mute who lives in a small southern town. Although he is considered a central character, there are four other characters who we learn more about than Singer. This is due to the other characters' lack of concern for Singer as a person; the characters' perceived relationship with Singer is more important to them than their actual relationship.
The setting is an impediment for all the characters because it serves as a figurative anchor that weighs them all down. For Mick Kelly, she is trying to find out who can she be beyond the confines of this town. She is trying to escape her socioeconomic status through her love of music and education, but in the end must accept a job working full-time (at the sacrifice of her education) in order to help support her family. The only person she conveys these dreams to are Mr. Singer. This is ideal because he cannot communicate with her in a conventional sense, and like the other characters in the text, she interprets his communications as she pleases. She develops and matures throughout the text from an immature, tomboyish and sometimes sassy teenager, to a slightly jaded realist who must accept her role in her family and the town.
Dr. Copeland is an African-American doctor who is fighting for racial equality in the segregated south. As an educated African American man, he is angered more than his contemporaries about the inequities and prejudice he endures. These feelings compounded with the disparities between himself and his family result in an extremely isolated character. Like Mick, he goes to Singer to convey his unhappiness and feels vindicated by their relationship (again - though Singer does not really communicate with him). At of all the characters in the text, Copeland and Jake are probably the most tortured and feel the most ostracized by society for their beliefs and views.
Jake is an outsider because of his political views. He is considered a socialist by most people in the town and has a tendency to drink and be violent. Like Copeland and Mick, he is drawn to Singer because he sees what he wants in Singer; he does not really get to know the man at all. Jake differs from the other characters because there is a darkness about his character that is illustrated with his suspicion of society and government. This is compounded by the impending war.
Biff is the final character who is drawn to Singer. Biff is a sad character because he is a man without dreams. After his wife's death, Biff's dreams and hopes of having a family and being a father are destroyed. He is resigned to observing life rather than being a part of it. As the owner of the town diner, this is easy for him to do. As a result of his observations, we are led down a unique path with Biff; we are able to read his feelings about the other characters and he reveals his feelings about his own purpose (again focused around being a parent and rearing children), rather than simply hearing his lamentations and personal anecdotes.
It is ironic that Biff, Dr. Copeland, Jake, Mick consider Singer an integral part of their lives, but Singer does not necessarily feel the same. When Singer commits suicide, it impacts each of them differently and profoundly.