The Immortal Six Hundred were 600 Confederate officers who were held prisoner by the Union Army in 1864-65. In the summer of 1863 when the Confederacy passed a resolution stating all captured African American soldiers and the officers of colored troops would not be returned. The resolution also allowed for any captured officer of colored troops to be executed and any captured African American soldier be sold into slavery. The resolution caused a breakdown in the exchange captured soldiers as the Union demanded all soldiers be treated equally. The Immortal Six Hundred were one group of officers who could not be exchanged.