What are three advantages the north had in the civil war?

Population, Industrial development and transportation.

Explanation:

Population - Within 23 Northern states against 11 Confederate states and a rate of almost 4 to 1 in human resources, the North exercised a strong unbalance in the population element. Nevertheless, the Confederacy mobilized a high percentage of its military-age white men, proportioning an army almost equal in size during the first year of the war.

Industrial development - There was a strong disparity between the North and the South when we talk about Industrial development. Since the beginning, the South maintained its rural tendency and lack of industrialization, but during the Civil war, this decision paid its price. The Confederate states were only responsible for 7% of all the nation's manufactured goods.

Transportation - The other Northern advantage was in the transportation sector. The North was responsible for 70% of all rail lines and had a superior number of wagons, horses, ships and railroad locomotives than the Confederate states. This superiority made much easier to move people and supplies during the course of the war.