The document summarizes copyright duration rules in the United States. It explains that under the 1909 Copyright Act, copyrights had an initial 28 year term that could be renewed for another 28 years. Many works fell into the public domain due to failure to renew. The 1976 Copyright Act replaced this system with a single copyright term based on the life of the author plus 70 years. The document provides details on determining copyright status and term length for works created before and after 1978. It also discusses some exceptions and amendments related to foreign and restored copyrights.