What you are reading and think what is in the text so you can understand it better.
When General Grant took command, the Union Army was still exchanging prisoners of war. This allowed each side to return their men to their country to fight again. Grant knew that the Union had more men and could produce more weapons than the Confederate. So he ended the prisoner exchange. This of course resulted in more men held in prisoner of war camps and creating problems for both sides, resulting in many deaths in these camps---both in the North and in the South. Grant also pressed his troops to stay on the attack. In some battles, his casualties were very high but he still knew that the Confederates could not replace their losses as easily as the Union could. Grant used General Sherman to force the war onto the civilian population and the industrial centers of the Confederacy. This was a new concept to most commanders. War was a duel between armies on the field of battle. The destruction of the industrial sites prevented an enemy from arming his troops and conducting war.
