When Miss Emily Grierson, the town recluse, dies at age seventy-four, she is buried with
the representatives of those august names where they lay in the cedar-bemused cemetery among the ranked and anonymous graves of Union and Confederate soldiers who fell at the battle of Jefferson.
Let's look at the details and symbolism this description suggests.
Miss Emily is indeed a representative of an august name, one of the last of the upper-class Griersons, yet those august names have decayed over the years as the bodies of their representatives decayed in the cemetery. Times change. Social classes change. The high families of the town fade into the past.
The cemetery is “cedar-bemused,” so filled with cedar trees that one can hardly see the graves. They are lost in trees as their occupants are lost in time. Miss Emily, too, is lost in time. She is a person of the past, unwilling to interact with the present, bemused by the dust and darkness of her house.
When she dies, Miss Emily rejoins the people of her age (or a little before), those Civil War soldiers who died long ago. It seems rather odd, though, that the narrator emphasizes that Miss Emily is buried among the ones who died at the battle of Jefferson. Perhaps it suggests that her own life has, in many ways, been a battle and death.
Some of those Civil War graves are anonymous. This, too, is rather symbolic. Miss Emily is not anonymous in that no one knows her name, but she is anonymous in that no one knows her character or knows much about her life or what goes on in her home. She is, for all practical purposes, an anonymous character in town. She has cut herself off from the rest of humanity.
Indeed, while Miss Emily's burial place seems rather unusual, it is actually quite fitting.