Q. What were the north's economic strengths

The North had a greater industrial advantage.

Explanation:

n 1860, the North manufactured 97% of the country firearms, 96% of its railroads, 94% of it cloth, 93% of its pig iron and over 90% of its boots and shoes.

the completion of the erie canal spurred the first great westward movement of american settlers, gave access to the rich land and resources west of the appalachians and made new york the preeminent commercial city in the united states.

the answer is title i subtitle b