What does the name Calpurnia mean, and what does it have to do with To Kill a Mockingbird?

Calpurnia from To Kill a Mockingbird shares her name with Julius Caesar's wife (sometimes her name appears as "Calphurnia").  Calpurnia from history was actually Caesar's second wife.  He most likely married her because she was the daughter of an influential Roman, and the marriage gave Caesar more power.

While it would not be accurate to compare Atticus to Caesar other than in saying that both were superb, respected leaders and strategists, Calpurnia from the novel does share some similarities with Calpurnia--especially with Shakespare's version of her in Julius Caesar. For example, both women are dependable and loyal partners to the leaders.  Atticus trusts Calpurnia to raise his children and to watch over them when he cannot be home.  Caesar had wronged his wife repeatedly by being unfaithful, but she still cares about his safety and tries to warn him not to attend the Senate meeting. Similarly, Harper Lee's Calpurnia does share in some of the strange superstitions and traditions of Maycomb even though she is a sensible woman, and Caesar's wife tries to prevent him from going to the Capitol by telling him about a dream she had and reminding him of the soothsayer's warning.

Lee's Calpurnia is, of course, a much stronger and admirable character than Shakespeare's Calpurnia, but nonetheless, both women faithfully support men who hold highly positions in their communities.