Capt. A. Dickert in his book "History of Kershaw's Brigade" makes many stricking comments about the loyalities of the slaves accompaning the Army of North Virginia. That for the most part they were as free as the wind to roam the countryside foraging for food and such for their mess, or officers. That they would disappear on their hunting and be gone all day away from the Army to reappear at the end of the day with their provisions to fix the evening meals and chores. He commented that as far as he knew almost none deserted even when the ANV was in Maryland and Pennsylvania.
I know that this isn't the common impression one would have. That is why it is so stricking in contrast to that impression.