More supplies, more weapons, more firepower. The North had the manpower, weapons and artillary whereas the south had less firepower, but they knew the land and area as well as had the leaders, causing a more balanced war.
if you have more factory’s, you have more supplies. back then when workers laws were bad, you could get away with paying your workers bad. so you made more money on the supplies or whatever the factory makes, then what you spend on paying your workers.
