Library of Congress Digital Collections: Newspapers, photographs, documents, and other materials from the Library of Congress's extensive collections.
Making of America: The Cornell University Library Making of America Collection is a digital library of primary sources in American social history from the antebellum period through reconstruction.
Documenting the American South: Contains texts, images, and audio files related to southern history, literature, and culture, from the University of North Carolina libraries.
Cold War International History Project: from the Wilson Center
EuroDocs: Online Sources for European History: A directory of primary sources sites compiled by Brigham Young University