By John Ostapkovich

PHILADELPHIA (CBS) – As we look at this area’s connection to the assassination of President Kennedy, which happened 50 years ago Friday, we look back on a piece of the story that almost got away.

Steven Raab is a respected autograph merchant from Ardmore whose RaabCollection website currently features eight documents signed by JFK, but after a former White House Chief if Staff died.

“His family was selling all his memorabilia and there at the bottom of the box was something people had been looking for for 30 years and not found,” Raab said.

Recordings of conversations aboard Air Force One after the assassination, which two Presidential libraries supposedly had. The recording was digitized for comparison.

“We found, really to our astonishment, that there was a lot of new material and that these were the previous version which had since been lost, and the present version at the Kennedy and Johnson libraries, those had been edited down,” he said.

Raab says JFK remains in the small minority of famous figures “with legs” among collectors, whose reputation still inspires.

John Kennedy, and later President Kennedy, was in Philadelphia many times, but only once did it result in a plaque outside a national icon.

More tourists than natives probably see the plaque, because it’s embedded in the sidewalk within the security cordon of Independence Hall. It marks the speech JFK gave on that spot July 4th, 1962.

credit: John Ostapkovich/KYW)

credit: John Ostapkovich/KYW)

National Park Service museum curator Robert Giannini says Kennedy connected our Constitution, crafted within those walls, to a debate overseas.

“Kennedy was giving the speech more or less to try to pull together some of the European countries, especially England and France at the time, to bring them together and a sort of a Union. He was advocating a union, as well as West Germany.”

The plaque, installed in June of 1964, lies about 10 feet from a similar presidential marker, commemorating Abraham Lincoln.