Answer:
The South's dependence on European goods
Step-by-step explanation:
The factor that contributed most to the industrial advantages the North had over the South at the beginning of the Civil War was "The South's dependence on European goods"
This is evident in the fact that the North has the seaport and the European goods on which the south depended would have to pass through the seaport in the North, in which they put outrightly blocked. Thereby, the South was unable to import goods and weapons from the Europeans.