Answer:
For the creator, the copyright duration is the lifetime of the author plus 50 years.
For a corporation, the copyright duration is 75 years.
Details:
The copyright Act of 1976 was a revision of the previous copyright Act of 1988.
Another revision enacted by the 1976 copyright law was to increase the extension of copyrighted material before 1978 that was not in the public domain. The increase was from 28 to 47 years or a total duration of 75 years.
