Between 1861 and 1865, American Civil War prison camps were operated by the Union and the Confederacy to detain over 400,000 captured soldiers. From the start of the Civil War through to 1863 a parole exchange system saw most prisoners of war swapped relatively quickly. However, from 1863 this broke down following the Confederacy’s refusal to treat black and white Union prisoners equally, leading to soaring numbers held on both sides.
Records indicate the capture of 211,411 Union soldiers, with 16,668 paroled and 30,218 died in captivity; of Confederate soldiers, 462,684 were captured, 247,769 paroled and 25,976 died in captivity. Just over 12% of the captives in Northern prisons died, compared to 15.5% for Southern prisons.
Lorien Foote has noted, “the suffering of prisoners did more to inhibit postwar reconciliation than any other episode of the war.