Williams depicts the South in transition, moving away from an agricultural to a more industrialized society:
The region's agrarian economy, which had been in decline since the Confederate defeat in the Civil War, suffered further setbacks after the First World War. A labor shortage hindered Southern agriculture when large numbers of male laborers were absorbed by the military or defense-based industries. Many landowners, faced with large areas of land and no one to work on it, moved to urban areas. With the increasing industrialization that followed during the 1920s through the 1940s, the structure of the work force evolved more radically yet, incorporating large numbers of women, immigrants, and blacks. Women gained the right to vote in 1920 and the old Southern tradition of an agrarian family aristocracy ruled by men started to come to an end.
Writing of the play's setting, Williams noted that "I write out of love of the South ... (which) once had a way of life that I am just old enough to remember—a culture that had grace, elegance, an inbred culture, not a society based on money." Through the destruction of Blanche and her struggles with the contradictory demands of society, Williams expressed a lament for the destruction of the old South, making clear his understanding that such change was inevitable.
- from enotes, historical context