And another thing to consider is that many thousands of soldiers had proper burials and proper markers---for that time period. As the example I pointed out in the beginning of this thread. There were Confederate soldiers dying from wounds from the Battle of Jenkins Ferry in the Princeton, AR hospital. In those days graves could be properly marked with wood crosses, rocks or newly planted trees. Cedars were popular. Is not that what really matters, that these soldiers were cared for after death with respect by their contemporaries, in their time?
Compare that to Camp Douglas, where six thousand prisoners were buried in swamp land, nary a marker until a monument was erected in July 1893.
http://www.censusdiggins.com/prison_camp_douglas.html