Pose with hand inserted in coat
The above image is from the Civil war. That site has many interesting images from the civil war, probably wet plates?
Anyway, the pose--with the hand inserted into the partially unbuttoned coat--I have seen that in lots of old pictures. What's the explanation? Did people put their hand in their coat like that as a matter of course and the photographs just reflect a popular pose, such as a pose with the hands in the pockets?