The overall weakening of America as a result of the Civil War is apparent. One direct result was the flood of immigrants that 'rebuilt' the base of the country. There were entire regiments of Irish Immigrants that fought for the North. Those men, the ones that survived absolutely powered America into the 20th century.
The costs were appalling. 24,000 deaths in two days at Shiloh. Less than a year later more than double that at Gettysburg. The killing of humans on an industrial scale.
Yes, that's really an unfortunate and painful aspect. Stay blessed.