Final answer:
The Confederacy committed war crimes against African American Union soldiers, notably at the Fort Pillow Massacre in Tennessee and during the battle at Poison Spring, Arkansas, where they killed surrendered and defeated black troops, underscoring the racial hatred and violence of the era.
Step-by-step explanation:
The question revolves around two instances of war crimes committed by the Confederacy against African American soldiers in the Union army during the Civil War. Firstly, the Fort Pillow Massacre in Tennessee, where Confederate troops under Major General Nathan Bedford Forrest overran the fort on April 12, 1864, and executed numerous African American soldiers after their surrender, which led to a cessation of prisoner exchanges between the Union and the Confederacy. Secondly, the battle at Poison Spring, Arkansas, where Confederate forces and their Native American allies massacred African American troops from the First Kansas Colored Infantry after their defeat.
These events were not only military actions but also exemplified the racial prejudice and brutality African American soldiers faced. Union reports and newspapers highlighted these atrocities, especially the savage nature of the killings, bringing them to national attention and increasing Northern animosity towards the Confederacy.