I did a little poking around and found the photographer died in 1877. That fact is inconclusive regarding your tintype being CW, but I did discover the photographer's son was in the Union Army. It stands to reason that he would have photographed his son in uniform. Horace B. Wilkinson was mustered in to Company B of the 17th Illinois Volunteer Infantry in 1863. Later he transferred to Company I of the 8th.
Thanks so much--this is very helpful!!! I wasn't very clear about the type of photo-- there were several tintypes in the collection but this one is a cabinet card(?) and not metal. Sorry for being misleading!
Is this the same guy?
View attachment 1762608
I want to say 'yes' but it's hard to know for sure. Anyone have access to facial recognition software?