America's first Civil War, the Revolution, is again coming into its own. Three outstanding books on the subject have appeared within the last few months; Fleming's Beat the Last Drum -- the surrender of Cornwallis; Wilcox's recent critical biography of General Clinton, Portrait of a General, and this present excellent study of the naval battle fought off the Chesapeake on Sept. 5, 1781, between French and English fleets. The battle, fought in hit-or-miss fashion between a French fleet under Admiral De Grasse and a British fleet under Admirals Graves and Hood, lasted two and a half hours and few Americans today have heard of it. Everyone taking part in it later wanted to forget it, but it resulted in an indecisive French victory the author terms ""one of the greatest naval victories of all times,"" which by preventing the British from relieving Cornwallis at Yorktown assured his surrender and the end of the war. The account of the battle itself takes up only a small portion of the book, the rest being devoted to the backgrounds of the war, brief biographies of politicians and officers on both sides-""architects of defeat and victory,"" to the reasons behind Cornwallis's fatal decision to fortify himself at Yorktown, and to puncturing long-accepted theories as to why France sent ""foreign aid"" to America. Carefully documented and highly readable, filled with fascinating details of 18th-century naval warfare, the book will appeal to naval buffs ashore and afloat and to all historians of America's first Civil War.