The correct answer is C) it was the first modern war.
The advanced weapons, new technologies, and total warfare led historians to conclude about the Civil War that it was the first modern war.
Historians consider that the technology used during the Civil War was ery modern for the time. The new technologies that were used during the US civil war were air globes and even some kind of submarines. There were also modern rifles that had better accuracy in long distance shots. The soldiers used the telegraph for better communications and make better decisions on when to attack or where to go.