This is an antique photo of a man in a uniform of some sort, probably early 20th (maybe late 19th) century.
I'm not sure what kind of uniform it is, but it has a military look about it. Having a military look doesn't necessarily make it military, but on the other hand, there is a good possibility. The overall appearance is right - a man with short hair standing more or less at parade rest. Also there are shoulder epaulets, the "U.S" insignia on the collar, plus what looks like crossed swords behind it. I can't see that clearly, so I could be wrong, but if it is crossed swords, then this is most likely an early military dress uniform of some sort.
The photo is mounted on dark cardboard, and embossed in that cardboard is "Monroe Ft. Sheridan". I believe Monroe is the photographer & Ft. Sheridan is the location - specifically Illinois.
But I don't know for sure, so I hope someone who is expert in military uniforms (specifically US Army) will jump in and straighten me out if I'm wrong.
Anyway, it's a neat photo.