Gustavus V. Fox (1821-1883) was the first assistant Secretary of the Navy, and effectively the principal director of naval operations during the Civil War. 

Fox had served in the fleet for nearly 20 years (1838-1856), distinguishing himself in the Mexican War, before resigning to enter the shipping industry.  In August of 1861 President Lincoln appointed Fox Assistant Secretary of the Navy, to aid Secretary Gideon Welles in building a strong, efficient fleet to carry on the war.  Fox soon proved more than just an able administrator.  A talented strategist, for much of the war Fox was effectively the "Chief of Naval Operations."  In this biography, Ari Hoogenboom, noted for his Rutherford B. Hayes: Warrior and President (1995), naturally focuses on Fox's role in the Civil War, but nevertheless opens with several chapters that discuss, often incisively, the man's early life and career.  One he reaches Fox's service as assistant secretary, Hoogenboom deftly shifts from administrative to operational matters, alternating chapters devoted to the problems of policy and procurement (e.g., "Ships for  the Blockade") with chapters on operations (e.g., "Implementing the Blockade," "The Mississippi"), and occasional forays into strategy and diplomacy ("Commerce Raiders and Ironclad Rams").