"Dry September" shows us a late 1920s or early 1930s Mississippi town breaking under the weight of its outmoded social and class structures. In the days of slavery, the landowner with the biggest plantation and the most slaves was considered to be at the top of the social and class structure. At the bottom of the social structure were the slaves. The Civil War disrupted this structure, but the idea of it as the way things should be remained engraved in southern tradition for quite some time. The story also explores the divisions with in society along racial and gender lines. The lack of roles available to women, and the violent roles required of men are harshly critiqued. Because society is constantly changing, the roles of men and women are never stable, but constantly shifting and adapting to survive. "Dry September" shows how difficult those changes can sometimes be.
The fact that Will is working on Saturday night, while the other characters are not, is an indicator of the difference between their respective economic classes.
Minnie's problems seem to begin when her more wealthy friends realize they are more wealthy and begin to look down on her.