Generals had often won by attacking enemies with larger armies. Both sides used tactics during the Civil War. Defenders used several other Tactics to fight off large forces.
19.4 Military Tactics and Technology
This isn't over, it'll never be over.
Defending Troops tried to find high ground. From there, they could fire down on their attackers. Defenders dug Trenches or deep Ditches, or they built dirt walls. They took cover in the Trenches or behind the wall as the fired at the enemy. If the attackers had to cross open ground they would suffer many casualties.
I'm not quitting until i'm dead
Defenders can shoot attackers before they get close and other technology made the civil war deadly.