You've got to be glad to see these guys in uniform. Especially the soldier on the left has the look of a person with real dignity. Was he a former slave? Most probably, but he certainly looks like he is fully in charge of the situation.

Nice to see that was documented!

As Susan pointed out, a well placed cannonball would have take that place out, however that wasn't the purpose and I'm guessing that this was nowhere near to a place where a cannonball could get at it.

In simple terms a cannonball is a direct-fire weapon - you aim your cannon at something and let fly. So, if you're entrenched, as at the Siege of Petersburg, which I believe included Dutch Gap, you avoid cannonballs by digging your shelter into the wall of your trenches facing the enemy.

A bomb is different. In the Civil War this would have been a hollow iron shell (probably ball shaped) packed with explosives and maybe some other nasty scrap metal. This would have a fuse attached. The bomb would arc through the and explode - hopefully over the enemy positions - where the iron of the shell, and whatever nasty stuff was inside would spread about in nasty chunks designed to kill and maim. The defense is to dig into a hillside and build a rudimentary entryway. The only thing that surprises me about this is that the Major actually allowed himself the luxury of a glass window. Glass shards can be as deadly as a chunk of iron. I suppose if the business part of the bomb-proof is far enough back that wouldn't be a problem.

I'm no weapons expert, but a well-placed cannonball would have taken that place in a heartbeat.

It's already been bombed.