From the Miller Center at the University of Virginia, a nonpartisan institute "that seeks to expand understanding of the presidency, policy, and political history, providing critical insights for the nation’s governance challenges." For each president includes essays, speeches, bibliographies, links to presidential papers, and information on access to private and public papers.
University of California, Santa Barbara project. Digital archive of some 148,000 documents relating to the U.S. Presidency, including the Papers of the Presidents, inaugural and State of the Union addresses, transcripts and videos of presidential debates, transcripts of campaign speeches, news conferences, etc.