Time for another question since this game is both confounding and confusing me. Take a look at the screen shot. You'll notice a CSA stack in Shenandoah VA, which just so happens to be the Army of the Shenandoah. Not really surprising so far. The catch is that particular stack, literally just one turn previous was besieging Norfolk. This means that in one turn that stack lifted the siege, and somehow moved all the way to Shenadoah, VA.....by rail for at least the final part of the trip. The other catch is that you'll notice that the Union controls all the railways leading to that location.
You will also notice another CSA stack sitting in Fredricksburg, which is the Army of the Potomac. This stack was also at Norfolk the previous turn.
How is it possible to move 2 large stacks so far in 1 turn, especially when at least one of them did not have a clear path?