Nearly three-quarters of feature-length silent films made in the US have been lost, and the legacy that put Hollywood at the forefront of the movie industry from 1912 to 1929 is endangered, the Library of Congress says.
The first comprehensive study of American feature-length films of the silent era unveiled by the library on Wednesday paints a distressing picture, with 70 per cent lost.
Classics films such as The Great Gatsby in 1926, the 1917 version of Cleopatra and actor Lon Chaney's 1927 London After Midnight are among movies considered lost in their complete form.
"The Library of Congress can now authoritatively report that the loss of American silent-era feature films constitutes an alarming and irretrievable loss to our nation's cultural record," Librarian of Congress James Billington said.
About 11,000 silent feature films of United States origin were released between 1912 and 1929. Only 14 per cent, or about 1,575, exist in their original format.
Of the films that did survive, 5 per cent are incomplete and 11 per cent of those that are complete are in lower-quality format or in foreign versions, according to the study.
"We have lost most of the creative record from the era that brought American movies to the pinnacle of world cinematic achievement in the 20th century," Billington said.
Oscar-winning director Martin Scorsese, an advocate of film preservation, said the findings were invaluable. His film Hugo was inspired by pioneering film-maker Georges Melies who directed hundreds of movies in the late 1890s and early 1900s.
"The research presented in this report serves as a road map to finding silent films we once thought were gone forever and encourages creative partnerships between the archives and the film industry to save silent cinema," he said.
In 1990 Scorsese established The Film Foundation, a non-profit organisation dedicated to protecting and preserving motion picture history. It has helped to save more than 560 films, according to its website.
The study, The Survival of American Silent Feature Films: 1912-1929 commissioned by the National Film Preservation Board, also showed that of the more than 3,300 films that survived in any format 26 per cent were found in other countries, and 24 per cent have already been repatriated.
The Czech Republic has the most American silent films found outside the US. The report credits overseas archivists with preserving many silent films.
The author of the study, historian-archivist David Pierce, also compiled an inventory to help bring American silent films back to the country.
The report recommended that a national programme be developed to repatriate silent films from foreign archives, as well as a campaign to document unidentified titles. It also encouraged studios and rights-holders to acquire archival master film elements on unique titles.
Pierce said the silent art form retained a rare resonance.
"It is a lost style of story-telling, and the best of the films are as effective … as they were when they were initially released," he told ABC News. "When you take away dialogue from a narrative story, it actually puts quite a challenge upon the creative people involved to tell the story entirely in a visual fashion. And it's that limitation, I think, which makes the films so effective."
Additional reporting by The Guardian