Linda --

We're talking apples and oranges here.

It's not usually difficult to find a Federal soldier, because the U.S. government went to great effort and expense to locate, identify and move all Federal soldiers to a National Cemetery. No such effort was made for Confederate soldiers buried in Southern states during the war, so burial sites for thousands of Confederates are lost forever.

Exhibit A:
Confederates buried in and around Corinth MS. Not only are there no marked burials in the immediate environs, no one seems to have any idea where they may have been buried. Thousands of Confederates died of wounds or disease in Corinth or within a short distance of the town, but no one knows where they are (or were).