Every writer is an author whether he is published or not.
Being published does not give you authority over your text. Your hand holding the pen does that. [I still hold pens.]
You do not need the Library of Congress to grant you copyright. The Library of Congress granting copyright only makes your legal claim stronger in the case of another writer trying to steal authority over your authorship.
Publishing is a means to divest writers of their authority, making them writers without authority.
A writers authorship is a pseudo authority, a kind of mask of authority over the text. Editors and publishers are always trying to usurp the authority of the author–mostly because author is in itself something that asserts authority irrespective of being published.
Publishers are leeches as are most editors–not all–who are in themselves frustrated men of writing without authority, without even authorship.