How could having more factories be an advantage during war?

It will give the people woth the factories more advantages. More weapons food and more

First, the Union had the large population, people to fight in the war and work in the factories to make war materials. The North also had the industrial base, the factories to make these war materials. The Union also was wealthier than the Confederacy and could finance the war ... But the Confederacy had advantages, too.