The United States suffered at least 291,557 battlefield combat deaths in WW2, and at least an additional 113,842 military personnel deaths from other causes than direct combat.

We did not casually waste our soldiers' lives as the Soviet Union did, and of course we had far fewer civilian casualties than the countries fought upon, but it was no picnic. That second category being notably smaller than the first is the reason WW2 ranks below the Civil War, when two-thirds of military deaths were from disease and other privations.