The U.S. Copyright Office's Catalog of Copyright Entries consists of 645 volumes spanning the period from 1891-1978, and cover all classes of works and all renewals. The CCE is now available online here. The 1978 volumes contain entries for pre-1978 registrations that were not complete at the time of publication of the 1977 CCEs. These entries appear in a separate section at the end of each volume. All registrations made under the Copyright Law that went into effect on January 1, 1978 are available online at the Copyright Office website.