Maycomb's history is very important to Scout and Maycomb is a character in the story.
Maycomb is mostly important because it is the county seat. It is apparently older than the state. Scout describes Maycomb and Maycomb County in great detail at various parts of the book. In the South, tradition is important.
Maycomb was an old town, but it was a tired old town when I first knew it. In rainy weather the streets turned to red slop; grass grew on the sidewalks, the courthouse sagged in the square. (Ch. 1)
Maycomb is a small town. It does not have very many streets, and most of the people stay there all of their lives. They all know each other. Its primary purpose is government.
Because its primary reason for existence was government, Maycomb was spared the grubbiness that distinguished most Alabama towns its size. In the beginning its buildings were solid, its courthouse proud, its streets graciously wide. (Ch. 13)
Maycomb County itself is rural. We know this by Scout’s description of it.
Atticus said professional people were poor because the farmers were poor. As Maycomb County was farm country, nickels and dimes were hard to come by for doctors and dentists and lawyers. (Ch. 2)
There are a few major families in Maycomb, and the families are well known. The farmers stay farmers, and the townspeople stay townspeople (professionals, for example). People remain in their given social status. Tradition and class are very important in Maycomb. In addition, outsiders are closely watched. This is why the children are so suspicious of their teacher, Miss Caroline.
Speaking of old families, some of them live above the law (or below it).
Atticus said the Ewells had been the disgrace of Maycomb for three generations. None of them had done an honest day's work in his recollection. … They were people, but they lived like animals. "They can go to school any time they want to, when they show the faintest symptom of wanting an education …” (Ch. 3)
The Ewells live by the old garbage dump. They go to school on the first day of school, and then go home. The school is full of Ewells, but none of them know how to read and write because they never learn, since they go to school for only one day each year. Yet they have bucked the system because everyone has given up on them and looked the other way—until Bob and Mayella Ewell attract attention with the case of the century, accusing Tom Robinson of rape.
People in Maycomb stick together. You can see this when Miss Maudie has a fire, and everyone comes out to help her.
The men of Maycomb, in all degrees of dress and undress, took furniture from Miss Maudie's house to a yard across the street. I saw Atticus carrying Miss Maudie's heavy oak rocking chair, and thought it sensible of him to save what she valued most. (Ch. 8)
This is one of the greatest things about a small town. While everyone knows each other, everyone also helps one another. Even though people might not mind their own business, they are always there for each other and willing to lend a helping hand when someone is in trouble.
Unfortunately, Maycomb is also prejudiced and racist. Atticus discusses this with Jack.
I hope and pray I can get Jem and Scout through it without bitterness, and most of all, without catching Maycomb's usual disease. Why reasonable people go stark raving mad when anything involving a Negro comes up, is something I don't pretend to understand … (Ch. 9)
Atticus worries that Scout and Jem might turn out to be racists too, before the trial is over, despite the fact that he has taught them otherwise. He worries about the influence of the trial, and what people are saying around town, on his children. He has always tried to teach them that people are people, but in Maycomb, black is black and white is white. Racism runs deep.
We get a little bit more information about Maycomb County in general at the pageant. Apparently, it was named for “Colonel Maycomb.”
She chanted mournfully about Maycomb County being older than the state, that it was a part of the Mississippi and Alabama Territories, that the first white man to set foot in the virgin forests was the Probate Judge's great-grandfather five times removed, who was never heard of again. (Ch. 28)
Scout probably already knew all of this. She grew up knowing all of it. As a child in Maycomb, Maycomb County’s history would have been something that she grew up on and was repeated to her year after year, because having a sense of place and heritage was so important.
There is a difference between a setting, and a setting used as a character. When a setting becomes a character, it takes on a personality all its own. It almost seems alive and living and breathing. Maycomb serves that function for this book.
You can tell how important Maycomb and Maycomb County are to Scout, because she mentions them throughout the book. This is how Maycomb becomes a character itself. It is more than just a setting. It is an ever-present reality to Scout, and part of her heritage and way of life that she can’t imagine living without.