Copyright - How to tell if a book is in the public domain

For 1978 onward, copyrights are online, and you can search the online records. Prior to 1978, though, the records are available in print and microform, both at the Library of Congress, and at other major libraries around the country, including many Federal Depository Libraries. A few libraries known to have a reasonably full set are the Carnegie Library in Pittsburgh, the Free Library of Philadelphia (in microform), the University of Chicago library, and the University of California, Los Angeles.