Approximate ratio of American deaths in the Civil War to American deaths in all other wars combined: 1:1

Total population of the eleven Confederate States in 1860: 9,101,090.
Total number of slaves in the eleven Confederate States in 1860: 3,653,870
Total population of the Union in 1860: 22,342,231²

Percentage of total American population killed in the Civil War: 2%
Percentage of total American population killed in World War II: 0.3%
Percentage of total American population killed in Iraq War: 0.001%

Number of Union soldiers killed during the Civil War: 360,000
Number of Confederate soldiers killed during the Civil War: 258,000
Total number of men killed during the Civil War: 618,000¹