the north had an advantage over the south. for one that had bigger numbers in the military. A bigger population meant more soldiers. And since most immigrants went to the north instead of the south they were an added bonus. They had 7x the manufacturing power of the south. So they could turn out more weapons and bullets than the south. the north also had a way better railroad system than the south. So they could transport goods faster and easilier than the south. They also had the navy, since the rebels had broken they didn't get any ships so the navy was solely the union's possession.