Welcome! I must confess, I am not familiar with that one, but I hope someone who does know sees this and can help you out!
His name was John Wood and he lived in Middlesex New Jersey (the same place i am living in...we never move LOL)It would most likely help if you gave us your G G grandfather's name and what state he was from.
OK, I found it.
Civil War CDV - Need Help Identifying Insignia - posted in EPHEMERA, PHOTOGRAPHS & MILITARY ARTWORK: Ive had this image for some time and was thinking about selling it. The soldier is wearing a buckle that says Washington Rifles. I did a bit of research and found that this was a NY militia unit...www.usmilitariaforum.com