Letting the Odum Institute speak for itself:
Data Archive Catalog
“The Odum Institute maintains one of the oldest and largest catalog of machine-readable data in the U.S. It has an extensive collection of U.S. Census data, including one of the most complete holdings for 1970 Census files. Other major sources of data include the North Carolina State Data Center, which distributes North Carolina census data; and the National Center for Health Statistics. Its National Network of State Polls archive is recognized as the largest available collection of state-level surveys. Also available are data from studies conducted by UNC social science faculty.”
Public Opinion Poll Question Database
“The Odum Institute’s Public Opinion Poll Database allows any researcher to search for specific poll questions among the more than 230,000 questions in the Institute’s archive by key words, date, study number, study title, or state. The system displays the full question text, study information, and frequency distributions, so it is useful both to users interested in looking up previous question wordings to develop questions for their own studies and to users interested in frequencies or in locating particular variables for statistical analysis.”
Instructions for downloading files.