At a time before the camera lens could capture the frenzy and terror of battle action, illustrators known as "Special Artists"--among them such famous draftsmen as Winslow Homer and Thomas Nast--created for the American public some of the most important and lasting images of the Civil War. Reporting for newspapers like Harper's Weekly and Frank Leslie's Illustrated News, the Specials brought a visceral immediacy to the clash, presenting rich and nuanced...