How many civilians were killed in the Civil War? How many soldiers were killed?

I believe that the first half of your question is unasnwerable,
despite the large amount of Civil War lore and statistics that is
available online.  Possibly the main reasons why this is the case are
that the vast majority of the fighting occurred in the Confederacy,
that record-keeping was much less careful and complete there than it
was in the Union states, and that there appears to be little hard data
(at least online) about civilian casualties in any case.

As one academic put it in a lecture summary:

"There is no reliable estimate of the number of Southern civilian
casualties, nor the cost in property damage.  By the end of the war,
much of the South lay in ruins, economically bankrupt and socially
turned upside down by the emancipation of four million black slaves."

Western Virginia Community College: The Civil War & Reconstruction
Lecture Summary 3: The War, Part 2 (1863-1865)
http://www.vw.cc.va.us/vwhansd/HIS269/Lecture3.html

The following book may help you, if you can find a copy
"Title:    The Civil War Almanac"
Author Name:   Bowman, John S. (Executive Editor)
Publisher:    World Almanac Publications, New York, 1983 

Hope this will help you

Kind regards
Ross (Australia)

Thank you to markj-ga and rossgmann-ga for your helpful Comments on
this question.  Calculating such a number as the civilian casualties
in the Civil War does seem to be problematical. It makes one wonder
from where come all the numbers that the news industry instantly finds
every day for such things.