American Civil War
AD – MPE: 0.12
The Polity IV-dataset does not analyse the Confederacy separately. It ranks the United States as a democracy. I think the Confederacy would be judged an “open anocracy”. So I classify both sides in the American Civil War as advanced democracies.
White cites estimates for the number of civilians killed in the Civil War from 1861 to 1865, which range from 0.05 to 0.1 million. These estimates do not include soldiers who died in captivity.
The Wikipedia-article called “American Civil War” cites estimates for the number of civilians killed which range from 0.1 to 0.2, including prisoner deaths. I choose 0.12 as the most plausible estimate.