The Copyright office is the official U.S. government body that maintains records of copyright registration in the United States. Althoough registration is not required for the copyright to be in effect, but U.S. authors must register their works before filing an infringement suit.
The Copyright Office is authorized under the U.S. Constitution, Article I, Section 8: “To promote the progress of science and useful arts, by securing for limited times to authors and inventors the exclusive right to their respective writings and discoveries”
The Copyright Office is currently located at: The Copyright Office is housed in the James Madison Memorial Building of the Library of Congress, at 101 Independence Avenue, SE, in Washington, DC. (See: Wikipedia)