This book is based on a real story. It starts immediately after the Civil War in a northern Maryland county that went both directions. In some families, some sons went Rebel and others went Federal. We watch Congress be rude to each other, but they don't kill each other, burn down cabins, kill horses, etc. This happened all over that area after the War.
The book is written in a number of first person sections and I expected it to be annoying, but she did it quite well.
The first few sections are people who see Martha Jane Cairnes shoot Nicholas McComas to death, verifying that she did it in cold blood. She insists on being hanged that day. The next section is long and is from Martha Jane. She was chaste, but when she met Nicholas McComas, she felt something in her heart. They become closer and closer and she starts to want sex, even though she doesn't quite recognize what she wants. During this time, the Cairnes' freed slaves leave the household because Martha Jane's mother was very rude to the mother. The adult son of the freed slaves goes to work for Nick and Nick provides a cabin for the family.
The next section is Nick and it overlaps Martha Jane's by a very short time. Nick has had a fair amount of sex and his own wandering makes him wonder about Martha Jane. She didn't scream when they finally have sex. She seemed to understand it too well. And she grew up with the freed slave that works for him. Could she have had sex with a Negro? That would be disgusting! Nick asks Martha Jane to marry him, though he keeps moving the date. He eventually moves to Pennsylvania near some Amish and runs sheep there. He comes home once and runs into Martha Jane, who insists on having sex with him. Nine months later, there's a baby. He accepts it as his, but wonders what color it is. One last time, they set up a wedding and Nick is actually just outside the window, but goes home. Martha Jane is broken and tells him that if she sees him again, she'll kill him. He comes back to the town for the Federal anniversary celebration of the end of the Civil War, she finds out, and heads to the saloon and kills him. He thinks as he dies that they'll be together in heaven forever.
The next group of sections are from her trial, a number of people in the court, and then a longer section by Martha Jane's mother. Her mother never really liked her and was furious when she had a baby before she was wed, and she was as ready for Martha Jane to hang as she was. But when she sees the very white baby boy with Nick's eyes, and how Martha Jane cares for him, she starts to change her mind. The jury comes back with a verdict, and you'll have to read the book to find out what that is.
You should read it anyway; I highly recommend it. Besides the family tree and information in the back, there's an article from the NY Times that covers the trial.
The background tells us a lot about what happened in that time and place, like a brocade drape where the story is embroidered on top, giving us depth as well as the story.