Read up on Camp Douglas, in Chicago, Illinois. Thousands of Confederate soldiers died of starvation, disease and exposure to the elements there, and the yankees had more than enough food and supplies to prevent that from happening. They did it on purpose. In Andersonville, the Confederate guards died at almost the same rate as the POWs they were guarding due to the hardness of the war. The Confederacy could not properly care for it's own soldiers, people or POWs. The Union could.