Here’s an interesting article about a slave named Jourdon Anderson who wrote a letter to his master in 1865 after he had won his freedom. The slave said he had no desire to go back to his old “family,” and he had the audacity to ask his former master for back wages. Apparently, a historian is writing a biography on Anderson.
Southern law made it a crime to teach slaves to read and write. Some slaves were literate anyway, regardless of whether or not they had help from their master or mistress. Slave letters are by no means unheard of, but the few we have are highly prized by historians.
Make of the letter what you will.