http://www.icpsr.umich.edu/index.html
The Inter-university Consortium for Political and Social Research (ICPSR), established in 1962, is an integral part of the infrastructure of social science research. ICPSR maintains and provides access to a vast archive of social science data for research and instruction, and offers training in quantitative methods to facilitate effective data use. To ensure that data resources are available to future generations of scholars, ICPSR preserves data, migrating them to new storage media as changes in technology warrant. In addition, ICPSR provides user support to assist researchers in identifying relevant data for analysis and in conducting their research