USS Langley (CV-1/AV-3) was the United States Navy's first aircraft carrier, converted in 1920 from the collier USS Jupiter (AC-3), and also the U.S. Navy's first electrically propelled ship. Conversion of another collier was planned but canceled when the Washington Naval Treaty required the cancellation of the partially built battlecruisers Lexington and Saratoga, freeing up their hulls for conversion to the aircraft carriers CV-2 and CV-3. Langley was named after Samuel Pierpont Langley, an American aviation pioneer. Following another conversion, to a seaplane tender, Langley fought in World War II.