Hello Margaret, and welcome to Rootschat.
Interesting photo. Is it on glass? Could we wee the whole thing please, uncropped?
If it's a glass photo, chances are it was done between 1855 and 1865. It would be better if we could see all of the edges. However, the people on the Armed Forces board are much better at uniforms than we are, so you might consider putting a link there, or one of us could do it.
Cheers,
China