A Pulitzer Prize historian and novelist turns back to poetry in a collection of songs and poems about the Civil War. They are lyrical, simple and occasionally somewhat too sentimental. And there is little that is unique or arresting in their imagery or thought. Yet their quiet tone, and the cumulative impress of small vignettes about battle-fields, dead soldier boys, the president, all told with a retrospective calm, have""an elegiac effect. They conjure up a sad, poetic, and almost nostalgic picture of war, leavin out the horror and the fear. In short, they move the reader without shocking him, and between the author and the subject, may attract a popular poetry readership.