I think it is d. Persian empire but I could be wrong :/
I want to say it is D, because I believe it was in Harpers Ferry where the fight occurred and he lost his (I believe) 5 sons and his own life afterwards.
11: because more railroads= more supplies moving quicker
12: because if you have more money you can buy more guns and ammo plus Pay more troops
14: Disease and lack of food killed the troops
15: They also had many more troops than the south so even though they lost 100,000 more they could bring more troops faster than the south could
The answer to the question is D
