What was the main driver of the economy in the North during the Civil War?

There was great wealth in the South, but it was primarily tied up in the slave economy. In 1860, the economic value of slaves in the United States exceeded the invested value of all of the nation's railroads, factories, and banks combined. On the eve of the Civil War, cotton prices were at an all-time high.

Explanation:

answer; /// i believe that the correct answer is( it left behind rich

the answer is a) high entry costs