ThisNation.com
http://www.thisnation.com/
From Jonathan Mott, Political Science professor at University of Oklahoma, a website providing information and primary source documents relating to American Politics. The site features narrative sections on the branches of government, the Constitution, and Federalism. ThisNation.com's Library offers web versions of prominent primary source documents, supreme court decisions, war messages, political essays, speeches, poems and more. In the Multimedia section, Presidential Profiles include images of the presidents and the text of Inaugural and State of the Union addresses.

Cato Institute
http://www.cato.org/ 
The website for the Cato Institute, a research foundation for U.S. policy studies. Their website has reports, studies, and briefings on issues such as free speech, Social Security, regulation, federalism, globalization and more. 

Center for Public Integrity 
http://www.publicintegrity.org/ 
Provides "the American people with the findings of our investigations and analyses of public service, government accountability and ethics related issues."  Reports cover governments at all levels, and focus on issues like campaign financing, the influence of lobbyists, and the privatization of water resources. 

Economic Policy Institute
http://www.epi.org/
The Economic Policy Institute is a non-profit, nonpartisan think tank that seeks "to broaden the discussion about economic policy to include the interests of low- and middle-income workers". The Institute's website features briefing papers, audio and video files, and policy memo's discussing contemporary issues. The site also offers statistics and statistical analyses of indicators such as the GDP, wages, and income. The site is searchable or browsable by topic area.

Policy Agendas Project
http://www.policyagendas.org/
From the Center for American Politics and Public Policy, the Policy Agendas Project "collects and organizes data from various archived sources to trace changes in the national policy agenda and public policy outcomes since the Second World War". The website features a Policy Analysis Tool which allows users to track issues over time. The data is collected from articles, congressional hearings, Supreme Court cases, State of the Union speeches, and more sources. The site also features articles and papers on the data collected. Also, Teaching Resources are available from the site, including Lesson Plans, activities, and exercises. 

Images of American Political History
http://bill.ballpaul.net/iaph/main.php
Posted by William J. Ball of the Department of Political Science, a collection of images spanning the past three hundred years in American Politics. These images are in the public domain. They can be searched or browsed by time period.

Miller Center of Public Affairs
http://millercenter.virginia.edu/
The University of Virginia hosts the website for the Miller Center of Public Affairs. The site offers content such as a Presidential Oral History Program, the Presidential Recordings Program Transcripts, and archived forums of national discussion and debate. Also, the Miller Center site also hosts 
American President (http://www.millercenter.virginia.edu/index.php/academic/americanpresident/) this online reference source a "comprehensive collection of material about the Presidents of the United States and the history of the presidency". Browsable by era and presidency, this resource features essays on aspects of each presidency and prominent figures in their administration, as well as presidential speeches and biographical information.

Institute for Policy Research
http://www.northwestern.edu/ipr/ 
From Northwestern University, the Institute's mission is to "stimulate and support excellent social science research on significant public policy issues and to disseminate the findings widely". The content includes working papers, policy briefs, and newsletters. Working papers are browseable by topic area, and all publications may be searched by a local search engine. 

The Living Room Candidate: Presidential Campaign Commercials, 1952 - 2004
http://www.livingroomcandidate.org/
From New York's Museum of the Moving Image, a site featuring campaign commercials. User can browse the commercials by year, issue, and type of commercial, or one can search by keyword. Free registration will allow users to save the commercials. Credit information is also available to aid in citing the videos. A link "For Teachers" will list lesson plans to be used in conjunction with the videos. 

History and Politics Out Loud
http://www.hpol.org/ 
A collaborative project of the National Endowment for the Humanities Teaching With Technology Program, Michigan State University and the National Gallery of the Spoken Word, this website offers audio files of speeches, conversations, and interviews of significant figures in political history. A search engine allows users to search the files, or browse by date, speaker, or title. 

Voting America: United States Politics, 1840 - 2008
http://americanpast.richmond.edu/voting/
From the University of Richmond, a website offering data on electoral history. The site features interactive maps for elections, with state by state data on turnout, votiing, and more. Many of the maps have accompanying commentary and are animated plotting the data over time.