Library of Congress
One of the largest collections in the world of printed and recorded materials; outstanding source for free images; resource for all copyrighted materials in America and beyond. LOC maintains collections of nearly all city directories and county histories in the U.S.; houses a comprehensive directory of all known copyrighted newspapers by timeframe and where they can be located today, in the important U.S. Newspaper Directory and Chronicling America; and offers comprehensive historical materials of all kinds.