Well without full context I would assume Trench Warfare because thats what 3 1/2 of the 4 year wars where full of.
Explanation:
While the war was going on, Northern writers and speakers referred to it as a “civil war” because of their belief that individual states had no right to secede from the Union.
There is no image but i would say Iraq or Afghanastan, please link the image if u can for more detail
