The burial of prisoners of war in soldiers' and national cemeteries dates to the Civil War, when the United States and Confederacy collectively held more than 400,000 prisoners in overcrowded camps and mortality rates were high. Under customary rules of war, the dead were interred near the camps or in national cemeteries created during and shortly after the conflict. Care of prisoner-of-war dead on American soil did not become an issue again until the world wars. During World War I, the United States held less than 6,000 enemy aliens and prisoners of war in internment camps. During World War II, an estimated 425,000 prisoners of war and enemy aliens were held in camps. Internationally accepted rules of war required that prisoners who died be buried according to their national customs, and unless claimed by family or country, their graves remain the responsibility of the U.S. government to this day. Twenty-three VA cemeteries contain more than a thousand enemy graves from the world wars, and Benicia Arsenal Post National Cemetery, Section 1, contains the remains of nine World War II prisoners of war, eight German and one Italian.