The Union had more resources. It controlled the factories, and had the raw materials and the resources to turn them into weapons and uniforms. The South had limited manufacturing resources. The only advantage the South had was familiarity with the territory, and closer food supplies.
At first, it looked as though the Union had all the advantages and this would be a short war. 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. The Union had an established army and government, but the Confederacy would have to build their army and government from scratch. Finally, the Union had a navy which they used to blockade the southern coast and to control the Mississippi River, cutting the South in half. But the Confederacy had advantages, too. The Confederacy would be fighting a defensive war, which is much easier than having to invade and conquer a territory, something the Union would have to do. Because the Union would have to invade the south, their supply lines would be much longer, and the Confederate army’s supply lines would be much shorter. Because they would be fighting on their own land, they could take advantage militarily of their knowledge of the land. They would be defending their homeland which would give them a strong incentive to fight. They would also be fighting among friendly people. Finally, some of the best military leaders, such as Robert E. Lee and Thomas “Stonewall” Jackson, chose to fight on the side of the Confederacy. It took Lincoln almost three years to find a competent commander in Ulysses S. Grant. It was because of these Confederate advantages that the war took so long for the Union to win.
One of the major advantages for the North was the fact that it had more of essentially every sort of resource that was needed for fighting a war.
Two of the most important kinds of resources that the North had more of were people and industrial capability. The North had a much larger population than the South. Furthermore, much of the South's male population was made up of slaves who could not be used as soldiers. In terms of industrial capability, the North had almost all of the factories in the country and the great majority of the miles of railroads. This meant that the North could produce and transport military materiel much more easily than the South could.
In these two major ways, the North had a huge advantage in terms of resources.
The union had more railways and more industries than the south.