Po'Sandy is not so much a story about a haunting as it is a piece on morals. However, multiple points within the story relate directly to the psychology behind why Sandy continues to linger.
The story itself condemns slavery. It assumes the readers are educated white people, and brings them to the level of those who have suffered due to slavery. The lead narrator, Uncle Julius, enlightens an ignorant, young, white couple on the events surrounding a slave named Sandy, and why his spirit is still haunting the old schoolhouse the wife wants to tear down.
Sandy, wanting to escape his life as a slave, begs his wife, Tenie, to turn him into a tree. He chooses a tree, most likely, because they are strong and rooted to their location: Something Sandy has never had. As a slave, he is considered property, and can be bought and sold whenever his owners see fit. He has the same rights as an animal, if that, and suffers immensely because of this. Although he despises his life, he is still tied to it because of his wife. Thus, instead of choosing to be an animal that can wander and escape the life of slavery, he chooses a tree. This also reflects his inability to truly break free of being a slave: As a tree, he is bound to the area where he is planted, and at the mercy of the outside influences around him, similar to his life as a slave. Tenie transforms Sandy back and forth between a tree and man multiple times before Sandy, as a tree, is finally cut down and transformed into a tree house by the very slave owner he was trying to escape.
Uncle Julius uses this story to put the couple in a predicament: If they destroy the school house, which is made from the 'bones' of a slave, rather than donate it to the descendants of slaves, they are, in a rather roundabout way, almost as bad as the slave owner himself. It is also a way for Uncle Julius to gander sympathy from the couple, in the hopes that instead of tearing down the school house, they will donate it.
Sandy's story doesn't end there, however. He continues to haunt the school house as a very rowdy and upset ghost. He continues to exist because he is still trying to break free of his chains, although it is not something he can manage. His decision to be turned into a tree left him tied to slavery, and, brought about his end sooner than it might have otherwise happened. Instead of fleeing his life as a slave, because it was the only life he had known he chose a life similar to it. He also displays a major character flaw through his decisions: The person who suffers most through his decisions is not Sandy himself, but his wife. After the tree Sandy had been turned into was cut down, Tenie fell victim to her own grief, dying in the school house. Sandy not only condemned himself, but the person who cared about him the most.
So why does Sandy continue to haunt the school house? It is probably because he still cannot break free of slavery. Through the tragedies that befell himself and Tenie, he is even more attached to the school house.Sandy does not know a life outside of being bound by outside influences and, as such, is still bound to the area closest to his past life. He is angry because, although he wanted to escape his life as a slave, he could not in the end.
At the end of the story Uncle Julius has convinced the couple not to tear down the school house. Instead, they will donate it to Uncle Julius and his acquaintances, who will use it as a place of worship. Uncle Julius comments that if the spirit of Sandy begins to act up, the word of God will do him a bit of good. This suggest that, perhaps, upon achieving enlightenment Sandy may finally be able to break free of the chains that have, and still, tie him down.
