Only if you're already good enough to drive nails at 1000 yards and want to shoot out to 2000 yards. Until then I'd suggest .308/7.62 - its cheaper, easier to find and still good from 300 out to 1000 yards.
I have DPSM LR-308 AP4...
Sight POSP3-9X42... basically a PSO-1. That sight is also good because it can be used on AK47 (but the chevrons represent different ranges). I like the range-finding scale on the left side of the scope.
In a civil war, can you really tell a good guy from a bad guy at 1000 yards?
It's not like 1861, when troops moved in Napoleonic masses and wore identical uniforms, with their regimental colors to the front.