Complex sentence: Torpedoes and torpedo boats became specialties of his, and he commanded the First Group of the Atlantic Fleet's Torpedo Flotilla in 1912 through 1913, and also several torpedo boats and destroyers during the 1910s and 1920s.
Split into simpler sentences: Torpedoes and torpedo boats became specialties of his, and he commanded the First Group of the Atlantic Fleet's Torpedo Flotilla in 1912 through 1913. Halsey commanded a number of torpedo boats and destroyers during the 1910s and 1920s.