In the troubled years leading up to the Civil War, newspapers in the North and South presented the arguments for and against slavery, debated the right to secede, and disputed the Dred Scott decision, denouncing opposing viewpoints with imagination and vigor. Although it is impossible to determine the precise effect of the newspapers on their readers, there is no question that they took the temperature of their communities and recorded the rising local agitations, unifying opinions, raising alarms, and cementing prejudices. Now in paperback for the first time, Lorman A. Ratner and Dwight...