"The American National Election Studies (ANES) produces high quality data on voting, public opinion, and political participation to serve the research needs of social scientists, teachers, students, policy makers and journalists who want to better understand the theoretical and empirical foundations of national election outcomes."
Primary documents on American presidents along with election data and other statistical resources from the University of California, Santa Barbara; it contains more than 77,000 documents, including the Public Papers of the Presidents from 1929 to the present.
"CAWP is nationally recognized as a cutting-edge research center, the leading source of scholarly research and current data about American women's political participation."
"ThisNation.com is a repository of basic information, resources and historical documents related to American Government and Politics." It was created and is maintained by Dr. Jonathon Mott, a political scientist at BYU.
An extraordinarily large site containing links to information about the Presidency organized topically under hundreds of alphabetical entries; maintained by Russell D. Renka of Southeast Missouri State University.
Maintained by Keith Poole of the University of California, San Diego, this site uses the NOMINATE data to estimate the ideological predispositions of congressmen, congresses, and political parties by analyzing roll call votes going back to the 1st Congress; includes publications and talks about the subject by Poole and collaborators.