Differences in regional economic development during the 19th century produced which of these conditions in the united states at the time of the civil war?
the north was the nation's main industrial area.
the south was the main destination for immigrants.
the north was the nation's main cotton-producing area.
the south was the nation's m ain transportation center for agricultural goods.

Explanation:

The American economy was caught in transition on the eve of the Civil War. What had been an absolutely rural economy in 1800 was in the first phases of an industrial revolution which would result in the United States getting to be one of the world's leading industrial powers by 1900.

However, the beginnings of the industrial revolution in the prewar years was solely constrained to the locales north of the Mason-Dixon line, leaving a significant part of the South far behind.

the doctrine of nullification recommended that states living inside the union have the one-sided, inalienable ideal to void any law made by the national government that could be esteemed illegal.

the united states was shaped based on a general agreement among its individual states. hence, it is inferred that under the hypothesis of invalidation, since the states are the establishment of the union, they have the ability to referee and disprove unlawful laws.