USS Langley (CV-1) 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 cancelled 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. During the Second American Civil War, the Langley sailed to Manila to join the newly-independent Philippine Navy, rather than allow herself to be captured by the Communists. Due to lack of money, lack of trained personnel, and the carrier's general obsolescence, she remained moored in the Philippines until the Japanese invasion in 1942. After the Philippines' surrender, Langley was sunk at anchor by saboteurs on May 8, 1942 to prevent her use by the Imperial Japanese Navy.