More Americans died in the Civil War than all other wars combined
From the Civil War Museum in Harrisburg, PA: “The number of war-related deaths in 1861-1865 is greater than the total number of American deaths in all other American wars.”

I’ve been stating that finding lately and wanted to cite my source for future reference. Estimates on deaths from wars are hard, as pages like How Many Died in the American Civil War? at History.com describe. Wikipedia’s United States military casualties of war links many sources.
You can define war deaths to include only people in the military or not, you can pick high estimates or low, and so on. I consider the Civil War Museum a credible source.
Its gift shop had signed books from podcast guest David Blight (so far I’ve only finished the one on Douglass):

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