[central_va]

I would put it this way,

Infantry - even
Cavalry - edge to the South
Artillery - overwhelming Federal advantage

[RayChuang88]

I'd put one more advantage to the Union: they had VASTLY better industrial capacity. The Union states could way out-produce the Confederate states when it came to armaments, and the the Union's amazing United States Military Railroad meant the Union could move a lot more troops, arms and other supplies to the front lines faster than the Confederates could.