Sharing Experience
In "The Blue and the Gray," you can mix and match your troops to put different units together. While it might seem like micromanagement, if you put less experienced troops in with more experienced ones, the less experienced troops will inherit the experience of the more seasoned veterans ̵2; provided, of course, you have fewer fresh recruits and more experienced soldiers.
Flankers
Whenever possible, deploy flankers to the sides of combat areas. While going straight in through the middle of the enemy's defenses is likely to result in heavier casualties, picking off units on the sides of the line with fast moving cavalry that can hit and fade away is just as valid a strategy in "The Blue and the Gray" as it was in the real Civil War.
Hammer and Anvil
Another strategy is to use the Hammer and Anvil maneuver. For this maneuver, you need to have a large block of troops ̵2; one that is preferably more than one and a half times the size of your enemy's forces ̵2; on one side of the enemy. On the other side, you need to have fast moving troops, such as cavalry, which can skirmish. This divides your enemy's attention, and you can crush its troops in between your forces.
Whites of Their Eyes
If you have cannons, use them as much as possible ̵2; especially if you're fighting an enemy that doesn't have the same long-range capacity. If you can destroy the enemy from a distance, making them come to you, it will help you win the battle much more easily.