Great picture, Andy, I love looking at it! Do you know who everyone is in the picture?
Your great-grandfather had quite a fierce look on him! Maybe the same look he sported when confronting the Confederate commander about his pony.
And the young man at the top of the picture has this smirk... makes me wonder what he did before the photo was taken. The young lady next to him, by comparison, is downright scowling and the young lady between them in the middle row is kind of looking haughty. The lady (?) at the left is looking bored IMO.
Love the young girl at the right edge - such a beautiful face and innocent expression.