Answer:
The years pass by, and Solomon almost loses hope. Then he meets a carpenter named Bass, an abolitionist from Canada who is hired to work on a building project for Epps. Bass learns of Solomon’s story and decides to help. He sends letters to Solomon’s friends in the North, asking them to come and rescue the slave from his captivity
Well a theme is the central message and lesson, so the way I learned is to come up with possible morals of the novel, then find evidence for each one, see which one is best supported, and use that one. If you think that will take too long, just find possible morals, then keep ruling them out until the one that makes the most sense is left, then find evidence for only that one.
Hope I helped you.