Flight of the Connie notes that April 6 marked an important anniversary in the U.S. scheduled airline business--47 years since TWA parked the last of its passenger-hauling Lockheed Constellations. The flight went from New York Kennedy Airport to the carrier's St. Louis base, with stops in Philadelphia, Pittsburgh, Columbus, and Louisville along the way. The morning after the flight, the aircraft flew to Kansas City where it joined 35 other retired Connies, the TWA Skyliner newspaper reports.
source: The State Historical Society of Missouri/TWA Skyliner
Among those on the retirement ferry flight were four crew members of another famous Connie flight: April 17, 1944's record-setting nonstop trip from Burbank to Washington National Airport, piloted by TWA majority shareholder Howard Hughes and President Jack Frye. The aircraft was the second C-69 (the Connie's military designation), but it was really TWA's plane--the company pushed for its development and built its reputation on the aircraft's speed and luxury.
TWA would operate more than 140 Constellations, including two freighters that held on for a few months after that April 6, 1967 journey. When the last passenger-configured one was parked, the carrier became the first U.S major airline to boast an all-jet fleet.
For more on the Connie's history as well as information on survivors, see this website.