In 2013, there was a story in Time magazine, regarding previously unpublished images of President Kennedy's motorcade in Dallas, Texas, in 1963 (fifty-three years ago today, as a friend reminded me, in an e-mail; I had not realized it was the anniversary).
The pictures were taken by an amateur photographer, H. Warner King, a Dallas jewelry wholesaler. Mr. King died in 2005. His daughter Sonia, an artist, said the following, in the piece in Time, about the aftermath of her father's death:
"As we were going through his possessions, I didn't want all his old slides at first, because I worried it might be some giant burden and I'd never look at them again. But I took them, anyway."
She said, in the article: "Recently, I began to sort through them, and came across a long red box labeled 'November/December 1963 Kennedy.' I found these pictures right away." She said: "Now, fifty years later, his photographs of the Kennedys finally see the light of day."
Ms. King said that her father had photographed the motorcade near the Turtle Creek section of Dallas, as it headed toward Dealey Plaza. Mr. King then drove to the Dallas Trade Mart, where the President was scheduled to speak, to take additional pictures; the speech, of course, never took place.
A couple of the pictures by Mr. King, seen here, are startling, in their sense of intimacy, and proximity--how close the onlookers appear to have been, in relation to the presidential limousine.
Here is the 2013 article, from Time, which includes additional pictures by Mr. King:
http://time.com/3430022/never-before-seen-photos-of-jfks-final-minutes-in-dallas/
(Photographs, above, by H. Warner King)