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. Lorien Foote has noted, "the suffering of prisoners did more to inhibit postwar reconciliation than any other episode of the war."