What is the historical reference to Atticus Finch and Calpurnia in To Kill A Mockingbird?
In Chapter One, Scout does give a brief history of her family and Maycomb. In that history, she does link Atticus' ancestor, Simon Finch, to General Andrew Jackson who fought in Alabama during the War of 1812. In discussing how and when the Finch's came to Alabama, Scout remarks:
I said if he wanted to take a broad view of the thing, it really began with Andrew Jackson. If General Jackson hadn’t run the Creeks up the creek, Simon Finch would never have paddled up the Alabama, and where would we be if he hadn’t?
Scout is referring to the Battle of Horseshoe Bend (part of the "Creek War" during the War of 1812) in which General Jackson drove the Creek Indians (Native Americans) "up the creek." Evidently, this battle paved the way for other settlers to come in, one being Simon Finch. General Jackson would later become president in 1828.
One historical reference regarding Calpurina is her church: First Purchase African M. E. Church. It was so named "First Purchase" because it was paid for by the earnings of the first freed slaves. Therefore, the church refers to abolition: the end of slavery.
On the level of Harper Lee's personal life, Atticus Finch is based on her (Lee's) father, Amasa Coleman Lee, who was also a lawyer who represented black defendants. The character of Dill was based on Lee's childhood friend, author Truman Capote.
In Chapter 12 when Calpurnia takes the children to church with her one Sunday because Atticus is out of town, Jem and Scout learn afterwards that Calpurnia's history is connected to their father's.
After the service, Jem and Scout ask Calpurnia about some things that they have observed, such as why the congregation does not save for hymn-books. Calpurnia laughs, pointing out the hymn-books "wouldn't do any good. . . They can't read." She explains that only three other church members besides her can read. Jem asks Calpurnia where she went to school. She responds,
Nowhere. Let's see now, who taught me my letters? It was Miss Maudie Atkinson's aunt, old Miss Buford.
Calpurnia explains further that there was a book from which Miss Buford taught her. "Bet you don't know where I got it," she challenges. Then, she tells the children that their Grandfather Finch gave Calpurnia a book entitled Blackstone's Commentaries. "Were you from the Landing?" Jem asks.
I certainly am, Mister Jem. Grew up there between the Buford place and the Landing. I've spent all my days workin' for the Finches or the Bufords. I moved to Maycomb when your daddy and your mamma married.