A curious omission. Just a couple of weeks ago I happened to be traveling near Appomattox, and had a few hours, so stopped in to visit the park there. They have all the details of the final battles, including casualty statistics. So the numbers are readily available.
They put the total war dead at (IIRC) 624,000 and since it's a national park, I'd presume that some kind of "official number."
In that final battle, near Appomattox, one civilian was killed -- a slave woman who did not evacuate with the others, was struck in her home by a stray bullet, and later died. According to the rangers, that was very typical of Civil War civilian deaths.
Finally, on the question of who had the more casualties, I think it was invariably true, that if the defenders stood their prepared ground, then the attacking army would suffer far more casualties.
Finally, on the question of who had the more casualties, I think it was invariably true, that if the defenders stood their prepared ground, then the attacking army would suffer far more casualties.
The Civil War initiated trench warfare. While set-piece engagements where two opposing lines stood and slugged it out caused high casualty rates (usually for both sides), they could not compare with sending units against entrenched positions. Fredericksburg is a prime example. Of course, the propensity for not calling off such lop-sided carnage was also a factor.