In what way did mathew brady’s photographs make a lasting impact on the country after the civil war?

The way that Mathew Brady’s photographs make a lasting impact on the country after the Civil War was: People saw the grim effects of war for the first time in his graphic photos

During the civil war, american people were divided into two group. After matthew brady's photographs were published (most of them had gruesome images of piling dead bodies), people realized that the war only bring misery for their own people and started to pulled out their support for the war.