They echo modern headlines - a shadowy underground organization orchestrating plans to bring down the government; bands of saboteurs slipping in from Canada to attempt coordinated acts of destruction; plans to poison water supplies and spread deadly diseases among the urban populace - but these and similar incidents were part of a Confederate strategy to wreak terror and consternation upon the North during the Civil War. Elements within the Confederacy, acting officially or otherwise, developed-and attempted-numerous plans to inflict terror and death upon the Union populace and bring down the...