I believe the three terms you are looking for is diplomatic, military, and economic ways.
I believe the answer is the Southern Region.
Despite the advantage in numbers, the northern forces still has several factors that could endanger the southern Forces, such as the north has more modern factories to produce weapon and about a third of the southern population were slaves that want the north to win.
They get droughts ans some water contain parasites which is not good to drink
True they may find evidence connecting other cases
