Yes, it is an original. The auction I bought it at, the auctioneer specializes in that area - photos, he buys and sells them & is good at identifying as far as the types of photos, but although he said Civil War, I still wondered about it. I didn't get a chance to talk to him after the auction, because I was in pain and was so ready to get home. If I was not going to buy this, I believe he was going to. He was bidding on stuff himself.
I also see as I look closer at the photo with a flashlight (my eyesight is horrible lately) that it does look very similar to your photo. It looks like the guy in my photo has a scarf or something around his neck. Can anyone tell me what that might be?