the Shuttle mainly used Lockheed Constellations until the Electras took over circa 1968; there may have been the occasional DC-7, but I don't recall seeing many of those at DCA back in the day ... I'm still occasionally irritated that, in my mid teens, I was unable to convince my parents to let me take a couple hours on a Saturday and use my own money to take a Connie from DCA to LGA and back
those may have been old planes, but they were scarcely "defunct"