Eisenhower introduced four propeller-driven aircraft to presidential service. This group included two Lockheed C-121 Constellations, aircraft Columbine II (VC-121A 48-610)[14][15][16] and Columbine III (VC-121E 53-7885).[17] They were named by First Lady Mamie Eisenhower for the columbine, official state flower of her adopted home state of Colorado. In addition, two Aero Commanders were also added to the fleet.[5]