A major theme explored symbolically in Streetcar is the decline of the aristocratic family traditionally associated with the American South. As the agricultural foundation of the Southern states was unable to compete with the new industrialisation, these families had lost their historical significance. During the First World War, the South experienced a labour shortage of agricultural labourers due to the large number of men who had to work in the military or in defense-related sectors. Due to their huge landholdings and lack of labour, many landowners relocated to metropolitan centres. With the increasing industrialization which followed in the 1920s through the 1940s, the structure of the work force changed further: more women, immigrants, and black laborers entered the workforce and a growing urban middle class was created. Women gained the right to vote in 1920 and the old Southern tradition of an agrarian family aristocracy ruled by men began to come to an end.

In the context of this economic and cultural environment, Blanche represents the female aristocratic tradition of the Old South. Belle Reve, her family home, is typical of the plantations that were being sold off as the aristocracy bowed out to the new urbanization. Blanche's ultimate fate can be interpreted as the destruction of the Old South by the new, industrial America, represented by an immigrant to the U.S.

Characters in the play are attached with their social class and they act according to their social class. On being a refined Southern belle who appreciates the finer things in life, such as art and poetry, Blanche bases her identity. But Blanche's upper-class sensibilities are contrast with the Kowalskis' working-class life in Elysian Fields. We found one important feature about Stella, the sister of Blanche who left to leave her upper-class background to join with Stanley. In fact Blanche though look as the part of a refined lady, she hides the fact of her scandalous behavior in her hometown has damaged her social standing. Her claim to represent a higher social class is a protective mask she dons to conceal her own decline in social standing. Stanley is driven to destroy Blanche by her conviction that she is superior to him despite the fact that he is of low status. Stanley overhears Stella calling him a "public avenger" or saying something he wouldn't do as a human when Stella characterises him as a "sub-human" He claims to expose her duplicity and protect Mitch and other guys from her traps. Stanley believes Blanche is encouraging Stella to dislike him. Stanley was successful in tearing Blanche's superiority mask. In this process Blanche looks towards him as an animal, the animal that Williams emphasizes with using as “inhuman jungle voices" and "lurid reflections." This happens at the time when Stanley rapes her.

 By the end of the play, Stanley's aggression has triumphed over Blanche's inherited family superiority. As she departs for the mental hospital, her old-fashioned manners are still apparent when she says to the men, ''Please don't get up." Their politeness in rising is a small gesture, however, considering their role in Blanche's destruction and in the fall of the Old South itself.