The link between warfare and morality in American culture is an originating one. The United States’ founding document, its Declaration of Independence, makes clear that a people’s natural right to be free and rule themselves begets the responsibility for acquiring and defending the same. This essay examines how American literature has and continues to adjudicate the three most pressing historical threats to the possibility of the United States warring justly: the Civil War, the World Wars, and the forever war. Relevant to each period, this essay explicates works of American literature with an eye toward exposing, rather than resolving, the central ethical problems of the times at the levels both of state and individual action.