It's Complicated!
•Everyone may use because copyright has expired or never applied
•Published before 1923 (except sound recordings)
•Published between 1923 and 1963 may have copyright renewed for an additional 67 year beyond the date of publication
•Published between 1964 and 1977 copyright is automatically renewed for a total of 95 years
•Created, but not published before January 1, 1978 are copyrighted for the lifetime of the owner plus 70 years
•Corporate author or work for hire—120 years after creation or 95 years after publication (The earliest any work copyrighted after 1978 is 2047)