(CBS News) CULPEPER, Va. -- There are moments that define America, and the record of many of them are stored in a vault in Culpeper, Va.

But these videotapes, some 50 years old, are deteriorating, and there is a race to preserve the history they contain.

"I think an important thing is to capture people's memories, to take people back to the day when they first saw Carol Burnett tug on her ear, or the day when Walter Cronkite couldn't hardly finish his sentence in November 1963, when Kennedy was shot," says Rob Stone, the Moving Image Curator of the Library of Congress....