John F. Kennedy's presidential limo served other presidents after assassination

The tragic Lincoln limousine is now at the end of the road in the Henry Ford Museum in Dearborn, Mich.

"The fiftieth anniversary of the assassination has really, really drawn people to that car for longer periods of time than is usual," said the museum's curator Matt Anderson.

To peer into the back seat is to ponder what might have been.

"You can totally picture, picture him there," said Anderson. "I think that's what a lot of people do when they come to visit the museum. They'll stand here and just sort of stare in the space and think about what happened."

Anderson told CBS News' Dean Reynolds that, when Kennedy had the car, it was "not armored in any way, shape or form."

"The tires were not bulletproof. There was no bulletproof glass. It did have a removable plastic top, but, again, it was just Plexiglas," he said. "It was no, no bullet resistance in that material. It's amazing to think of it, but they just didn't anticipate that kind of problem."

Code named X-100, the limousine, with all its tragic evidence, was flown to Andrews Air Force Base a few hours after President Kennedy's body.

Anderson told Reynolds that the car was driven back to the White House that night to start the investigation.

"They determined that the most practical thing to do was just to rebuild this existing car rather than to start from scratch, so, yes, they took the car down to the frame and rebuilt it as a true armored vehicle," he said. "The biggest change they made in modifying the car was putting in a permanent roof that could not be removed, and they surrounded the whole vehicle with bullet-resistant glass."

And then they put it right back into the presidential fleet.

"People are always just stunned when I tell them that this car was used and indeed used until 1977, so many years after the assassination," said Anderson.

Presidents Nixon and Ford rode in it as did Lyndon Johnson, who was two cars behind Kennedy that day in Dallas.

"He did use it, though I read time and again that he was not comfortable riding in this car, for obvious reasons, and only did it if he had to," said Anderson, "and when he first saw the car he took one look at that blue and said, 'No, we're not going to have that.' It was just too evocative of the assassination, so they painted it black very quickly, and black it remained. And then President Nixon had requested they actually cut a hole in the roof, so as the car exists today there is a hatch there. He can remove the panel, stand up and wave to the crowd."

But this car will forever be associated with a different motorcade and a different president on a much different day.