The physical address and phone number of the US Copyright Office is listed at the bottom of their homepage (see related link below)
The web address for the U.S. Copyright Office is www.copyright.gov. This site provides a range of resources related to copyright law, including information on how to register works, search copyright records, and access legal information.
The copyright office only gives one address, in New Delhi.
The US Copyright Office is the governmental agency which oversees, administers, and records copyright in the United States.
Contact information for the US Copyright Office is at the link below.
There are three ways to search US copyright records, online (see link below), in person, or you can have the records searched by copyright office personnel.
The US Copyright Office is within the Library of Congress, which serves as its deposit library.
copyright.gov
The US Copyright Office in Washington DC.
The U.S. Copyright Office http://www.copyright.gov/
Contact information for the US Copyright Office is at the link below.
The Copyright Office is part of the Library of Congress; the Librarian of Congress appoints the Register of Copyrights.
The US Copyright Office keeps them at the Library of Congress in Washington DC.