The North prevail in the war because it had more soldiers, more advanced technology, more money, better railroads so they could transport munition and goods easier and also a united army which had a united tactic which eventually was Total War.
The South was divided, they did not have a united army, each army had its tactics. Also, the south had little to none railroads, they had a hard time transporting goods and ammunition. Also, the South was more agricultural, so they had worse technology. The South would have won the war if it did not lose important battles and lost the Mississippi.
