Most Civil War enthusiasts have heard about the Hunley, the Confederate submarine that sank the USS Housatonic on February 17, 1864. Less well known, however, is that the Hunley was not alone in the water. Both the Union and the Confederacy built submarines; many were operational and patrolled for enemy ships. In Union and Confederate Submarine Warfare in the Civil War, Mark K. Ragan brings this little-known history to the surface. Ragan, who served as consultant on the 1999 TNT movie Hunley, uses contemporary letters, newspaper accounts, factory records, and log books to recount the early history of submarine warfare--from Bushnell's Turtle to the Hunley, from the Alligator to the Intelligent Whale. Many observers were enthusiastic about the new technology, describing it as "as formidable as it is economical." Others were violently opposed, labeling submarines "unchivalrous" and "infernal machines." For better or worse, the submarine was here to stay. Thoroughly researched, engagingly written, well illustrated, and featuring an introduction by Clive Cussler (who led the successful 1995 effort to locate the sunken Hunley), Submarine Warfare deserves a place on every Civil War buff's bookshelf. --Sunny Delaney