It helped people move and transport goods to other places
The answer is B.
The U.S. military is subordinate to the Federal (civilian) government. Note that the US Congress controls the budget, and that the President is required to ask for a declaration of war, and the Congress then votes to approve or disapprove the request.
Cotton in the usa was made in the south and if you got all of it done faster you can make it the more money you would make