His autograph signature ‘David D.Porter, Admiral’. On paper 3 x 5 inches, mounted at corners on part of an old album page. In good condition. Undated. Admiral David Dixon Porter (1813 –1891), United States Navy admiral. Promoted as the second U.S. Navy officer ever to attain the rank of admiral, after his adoptive brother David G. Farragut, Porter helped improve the Navy as the Superintendent of the U.S. Naval Academy after significant service in the American Civil War.