Arnold Schwarzenegger classic The Terminator is one of 25 films being added to the US National Film Registry.
The move will preserve the films - which include home movies and documentaries from the 1920s - and protect them from deterioration.
Other films on the list include the original 1933 version of The Invisible Man and John Boorman's 1972 thriller Deliverance, starring Burt Reynolds.
The films are selected annually based on cultural or historical significance.
"The registry helps this nation understand the diversity of America's film heritage and, just as importantly, the need for its preservation," said James H Billington, of the Library of Congress.
Over time nitrate and acetate-based films begin to deteriorate.
The Library of Congress is working to digitise and preserve endangered film and audio files. It also acquires a copy for preservation in its own vaults.
"The nation has lost about half of the films produced before 1950 and as much as 90% of those made before 1920."
The registry, established by the Library of Congress nearly 20 years ago, works with film studios that own the rights to the selected films to ensure original copies are kept safe.
Among the oldest films to join the list this year are the ground-breaking 1929 film Hallelujah, featuring an all-black cast, and 1910's White Fawn's Devotion directed by James Young Deer, the first documented American Indian movie director.