A lost film is a feature or short film in which the original negative or copies are not known to exist in any studio archive, private collection, or public archive.[1] Films can be wholly or partially lost for a number of reasons. Early films were not thought to have value beyond their theatrical run, so many were discarded afterward. Nitrate film used in early pictures was highly flammable and susceptible to degradation. The Library of Congress began acquiring copies of American films in 1909, but not all were kept. Due to improvements in film technology and recordkeeping, few films produced in the 1950s or beyond have been lost.
Rarely, but occasionally, films classified as lost are found in an uncataloged or miscataloged archive or private collection, becoming "rediscovered films".
^Pierce, David. "The Survival of American Silent Films: 1912-1929"(PDF). Library Of Congress. Council on Library and Information Resources and the Library of Congress. Archived(PDF) from the original on May 17, 2021. Retrieved November 18, 2020.