As Mary came from a wealthy Southern family, she was well qualified to write on her experiences. Her father was Stephen Decatur Miller, a distinguished southern lawyer, governor and congressman. Her upbringing and education gave her the opportunity to intelligently observe and record all classes of people, including the black families of slaves.

At the age of seventeen, Mary married James Chesnut, Jr., and was his confidante throughout their marriage. James was a wealthy planter, a defender of slavery and a staunch secessionist. He rose to prominence as a U.S. Senator, then was active in the South Carolina secession convention, served the Confederate army as a brigadier general, as well as an aide to President Jefferson Davis.

Through her husband, Mary became good friends with Varina Davis, the wife of Jefferson Davis. Through this relationship she formed friendships with many of the Confederate leaders; governmental and military. Through her clever and shrewd ways, she wrote about them all in her diary.

Following the war, Mary Chesnut rewrote her diary, condensing it from its original 400,000 words to about 150,000. She and her husband James had no children, so upon Mary's death on November 22, 1886, she left her diary to a friend.

In 1905 Marys' diary was first published under the title: A Diary from Dixie. The most reliable edition of Mary's diary was published in 1981 by Yale University Press, edited by C. Vann Woodward. It is titled: Mary Chesnut's Civil War. So valuable a work it is, it was the winner of the 1982 Pulitzer Prize in History.