Hello Landra:

I am not sure what you mean by "come across". Do you mean find or research? Outside of your family network?

If you do, perhaps a veterans group member of your uncle's unit may have a photo. You would have to find out what was the name of his regiment etc and find out if a veterans group knew your uncle. Your state archives may have photos

The Library of Congress, or National Archives have photos too. Was he in a foreign war? The Veterans of Foreign Wars is a very organized group and in recent years have encouraged Blacks to join their organization

Again, the key to your research is to know the unit your uncle was in and begin your research there.