Why did Harper Lee choose to end the novel "To Kill a Mockingbird" this way?
This story has been about the maturation of Scout, the protagonist and narrator. She has gone from an innocent and ignornant child to an open-minded young girl. She has learned about hate and prejudice, about compassion and hope. Harper Lee uses Boo Radley to symbolize some of these lessons, particularly Atticus' most important message - never judge a man until you have walked a mile in his shoes. At the beginning of the book, Scout and Jem and Dill judge Boo Radley. They accept the prejudice of the town and assume Boo is a scary and dangerous person. It is only fitting that the story end with Boo Radley. However, at the end, Scout is a friend to Boo and has much compassion and even love for him. She stands on the porch and sees the town from his eyes and understands him. She has walked the mile in his shoes.
But, of course, she is still young. To emphasize this, Lee chooses to add one last moment, this one between Scout and Atticus. Atticus tucks her in to bed, letting Scout and the reader know that she is still protected and will still be learning and maturing - she has to learn algebra, after all!