Demography

• Census Bureau
• Census Language Map
• Census Explorer
• Social Explorer
• National Longitudinal Surveys
• Population Index
• Bureau of Labor Statistics
• U.S. Citizenship and Immigration Services
• Pew Hispanic Center
• Proximity Demog-Econ Ranking Tables
• Washington: A World Apart
  

Religion

• Pew Forum on Religion and Public Life
• Association of Religion Data Archives
• Public Religion Research Institute
• American Religious Identification Surveys
• Pluralism Project
• Religion and the Founding (Lib. of Cong.)
• The Complete Guide to Historical Religion in America
• Barna Group
• Religion Data Resources

• Pew Research Center
• The Polling Report
• RealClearPolitics
• HuffPost Pollster
• Democracy Corps
• National Election Studies/ICPSR
• NORC
• General Social Survey
• Quinnipiac U Polling Institute
• Roper Center
• Gallup Poll
• YouGov 
• Harvard Harris
• Harvard IOP Youth Poll
• Washington Post polls
• Public Agenda
• USC Dornsife

• Presidential election exit polls through 1996 (NY Times)
• Congressional election exit polls 1992-2014
• State-level results and exit polls 1998
• Exit polls 2004 (CNN)
• Exit polls 2006 (CNN)
• Exit polls 2008 (CNN)
• Exit polls 2010 (CNN)
• Exit polls 2012 (CNN)
• Exit polls 2014 (CNN)
• Exit polls 2016 (CNN)
• Americans & the World (opinion on international relations)
• WorldPublicOpinion.org
• Pew Global Attitudes Project
• Kaiser Family Foundation polls
• American Association for Public Opinion Research