... as I strolled the grounds and looked at these old headstones, I was struck by the fact that they all died in 1862 and 1863 ... and many on the same day.

... after researching the issue a little, I found that the US Army established a prison camp near what is now downtown Louisville. It was basically a transient way-stop for prisoners being moved BUT it contained a military hospital to handle those who were too severely wounded to continue.

... medicine being what it was in those days, I think the majority of Confederate graves in this cemetery are of those soldiers who died from their wounds while being treated in the Field Hospital.