Wars are fought by soldiers, and this costs money. This why economics is discussed when dealing with the US Civil War. In many situations, a nation with a strong economy may have a better chance of achieving victory. It should be noted that "better chance" is part of the answer. Clearly armies requires arms, ammunition and food supplies. A nation with an economy that can deliver these things gives its armed forces the fuel needed to fight a war. The South had a disadvantage by not having an economy that could easily supply its armies with war supplies.