What challenges did the United States face after the Civil War ended? Check all that apply.

The future of more than four million formerly enslaved people was unknown.

The industrial economy of the North was failing.

The country needed to be reunified.

The costly war had resulted in debt.

Southern farmland and infrastructure were devastated.

A, C, D and E

Explanation:

answer: (fluidity)is the correct answer.

explanation: because of this characteristic, success on the battlefield depends in large part on the ability to adapt to proactively change events to our advantage as well as to react quickly to constantly changing conditions

it provided for equal trade rights among nations in china.