I was looking over the objective cities and I noted that Knoxville is not an objective city. I find this very odd considering how many times Lincoln ordered his Armies to take Knoxville and the determental effect not taking the place had on the careers of more than one Union General.
I also noted that there isn't really much Union sentiment in the areas around Knoxville which doesn't match the historical record.
One easy mod would be to make Knoxville an important objective, this would force both sides to fight for Eastern Tennessee like happened historically.