Which two characters in To Kill a Mockingbird are compared to a mockingbird? Why is the mockingbird an appropriate symbol for these two characters?...

In the final section of To Kill a Mockingbird, both Tom Robinson and Boo Radley are compared to a mockingbird in the sense that they are both people who are unfairly targeted because of qualities they cannot change. At the beginning of the book, Miss Maudie says, "mockingbirds don't do a thing but make music for us to enjoy." This speaks to the idea that there are certain people who are senselessly hurt or killed because they are easy targets. These people love to help and bring joy to others, but are often killed for no reason. 

Tom wants nothing more than to live his life freely and pursue his happiness, just like any white man in the south is able to do. He is a kind man who did nothing but help others and work hard for others his entire life. Mr. Underwood compares Tom's death to the killing of a mockingbird and describes it as a "senseless slaughter." Tom was killed for the sake of killing; it was an acceptable act to mistreat and murder black folks in the south, just as it was acceptable to kill mockingbirds for pleasure. 

In Boo Radley's case, his handicap led him to be hidden from society and sheltered by his family. The townspeople gossip, and children make fun of him and play tricks on him. Still, he went out of his way to bring happiness to the children, doing small acts of kindness that gave them hope. Boo even saved Jem's life when Bob Ewell tried to attack him. In many ways, Boo is unaware of the evils of the world, much like the sweet songbird for which the book is named. 

Both of these characters are kind, but they are also somewhat child-like. They believe if you show others love and kindness and don't harbor any ill-will toward a fellow human being, that kindness will be returned. They feel wronged when it isn't.

Boo, however, doesn't even realize the extent to which he is ostracized. He is not as wise to the ways of the world as others might be. He does have many adults in the town who he sees as friends, much like Tom has. Unlike Boo, though, Tom knows enough to feel that although he is innocent, his skin color makes it so there is no chance he will win his case. Tom knows that being accused of a crime against a white woman is as good as signing a death warrant if you're a black man in the south.