To Kill a Mockingbird was written in 1960 by Harper Lee (a law student from schools such as the University of Alabama and Oxford University). In it's first year of publication the book did something that most writers only dream about. It was chosen by three American book clubs as the best read: Reader's Digest Condensed Books, the Literary Guild, and Book-of-the-Month Club. To Kill a Mockingbird also sold more than two and a half million copies within one year of publication and had of 14 different printings. Although the title To Kill a Mockingbird has very little literal connection to the plot, the idea of a mocking bird is a significant theme that carries a great deal of symbolic weight in the book in three different ways.
In the story to kill a mockingbird is a representation of innocents destroyed by evil, the "mockingbird" comes to represent the idea of innocence. Therefore, to kill a mockingbird is to destroy innocence. Throughout the book, a number of characters (Jem, Tom Robinson, Dill, and Boo Radley) can be identified as mockingbirds "innocents who have been injured or destroyed. This connection between the novel's title and its main theme is made apparent several times in the novel. When Jem and Scout get their guns Atticus tells them, "Shoot all the Blue Jays you want, but remember to kill a mockingbird is a sin."" Also when Tom Robinson is shot, Mr. Underwood compares his death to "the senseless slaughter of songbirds,"" and at the end of the book Scout thinks that hurting Boo Radley would be like "shootin' a mockingbird."" Most important, Miss Maudie explains to Jem, "Mockingbirds don't do one thing but . sing their hearts out for us. That's why it's a sin to kill a mockingbird.".
Similarly, when it is revealed that Boo Radley is the one who had killed Bob Ewell while saving the children's lives, Mr. Heck Tate refuses to hold him responsible because he feels that it would invite unnecessary attention to Boo Radley, which he does not want.