What aspects of cultural identity are presented in the text?

Stella and Blanche come from a world that is rapidly dying. Belle Reve, their family's ancestral plantation, has been lost, and the two sisters are the last living members of their family and, symbolically, of their old world of cavaliers and cotton fields. Their strain of Old South was not conquered by the march of General Sherman's army, but by the steady march of time, and as Blanche's beauty fades with age so too do these vestiges of that civilization gone with the wind. Blanche attempts to stay back in the past but it is impossible, and Stella only survives by mixing her DuBois blood with the common stock of the Kowalskis; the old South can only live on in a diluted, bastardized form.