Commander James H. Rowan, USN or Commander Stephen C. Rowan, USN
This is a "Carte de viste" photograph, by McAllister & Brother, Philadelphia, circa 1855-1862. Originally captioned "COM. ROWAN" this man does not look much like Stephen C. Rowan's other photos, and could be James H. Rowan, who was dismissed from the navy in 1857.
Naval History and Heritage Command