In my area, my guess is that it probably belonged to a Cavalry detachment of Don Carlos Buell's Army of the Ohio.
I live in Northern KY and during the ACW my area was heavily fortified for the general protection of Cincinnati against Confederate invasion.
Elements of Braxton Bragg's Army of Tennessee actually did reach the Florence, KY area where there was a skirmish, and the scouts made it practically all the way to the Ohio River. The two main bodies however collided with each other in a little central KY town called Perryville, resulting in over 7,500 casualties.
Now you got me wantin' to unearth some CSA buttons... I know the "exact" place to go, but I would be arrested because it's in a state park...
On the other hand, I could pursue some private landowners nearby... problem is it's about a two-hour drive... I may do it this fall when the weather cools off, that way I can hunt all day and make the excursion more worth while.
There's a couple of city parks that may hold some items that I haven't checked yet...
Have you have thought about buying one of those electric power chairs (carts) and mounting a detector underneath? You could rig a little dye spray deally to mark each find and then come back later and sort of "rest" in that spot. Kind of gets ya ta thinking, don't it??