Further explication of the Bono summary by Jeri, found in Wikilaw; may not be completely accurate. The summary by Jeri, and the following, do not seem completely compatible.
(The 'officialese' from the government publication may not seem so dense after reading the following).

Has the thrust of the following summary (Wikilaw) been changed by subsequent modification? Someone familiar with U. S. copyright law please comment.

"The Act established the following terms of copyright protection:
-for post-1977 personal works, life of the author plus 70 years;
-for post-1977 impersonal works (works made for hire, anonymous or pseudonymous works), the shorter of 95 years from publication or 120 years from creation;
-for pre-1978 works, 95 years from the date copyright was secured either by publication with notice of copyrighr or in th case of unpublished works by registration.
All of the extended terms apply retroactively to any work in which copyright existed at the time of the Act, and to the works that were retrieved from the public domain by the 1994 law implementing the Uruguay round of the General Agreement on Tariffs and Trade (GATT).

Another special provision extends the term of works created but not copyrighted before 1978 (i. e., unpublished, unregistered works) by 20 years (by increasing their expiration date from 2027 to 2047) provided the work is published by December 31, 2002. Presumption of common law/state law copyright in pre-February 15, 1972 sound recordings is also delayed another 20 years, from February 15, 2047 to February 15, 2067."