What are the symbols in the novel To kill a Mockingbird ?

The title itself leads to a lot of symbolism. The
mockingbird is intended to represent innocence and "killing" the mockingbird is the loss
of innocence. Everyone experiences moments that permanently alter their view of the
world. Some people experience these things as young adults and, unfortunately, some as
kids who are forced to grow up too fast. A number of characters in the book are symbolic
of the mockingbird, or the loss of innocence. Certainly Jem. Also consider Dill, Boo
Radley, and Tom Robinson. They all experience things that take away some of their
innocence through some sort of evil or
wrongdoing.

Examples:

After
Tom is shot and killed, Mr. Underwood calls it "the senseless slaughter of
songbirds."

Scout says that hurting Boo Radley would be
like "shooting a mockingbird." (killing innocence)

Ms.
Maude tells Scout "Mockingbirds don't do one thing but sing their hearts out for us.
That's why it's a sin to kill a mockingbird."

Jem and
Scout's last name is Finch, which is a type of small bird (similar to a
mockingbird).