How can I determine who holds the copyright for a book?
Copyright registrations from 1978 to date can be searched online.
A search of registrations, renewals, and recorded transfers of ownership made before 1978 requires a manual search of government copyright files. You can do that yourself at the Copyright Office. Alternately, their staff will perform searches for a fee. For further information, see Circular 22, How to Investigate the Copyright Status of a Work, and Circular 23, Copyright Card Catalog and the Online File.