The VirtualRDC serves as an (informal) data archive for some historical time series, typically originally provided by the Census Bureau.
The full historical time series for the QWI are recomputed every quarter based on the most recent information, and released on a flow basis by the U.S. Census Bureau. Historical versions are available to users – up to four versions through direct web-based download at the same location as the most current version (http://www.vrdc.cornell.edu/qwipu/), and others upon request. Some versions may be resident on the Social Science Gateway's compute nodes, under /data/clean/qwipu/state/. Each version covers the entire historical time series. Versions are identified by the quarter in which they were released - R2012Q2 was released in Q2 (April-June) of 2012.
Early versions of the LODES data (then still called OnTheMap data) are available at http://www.vrdc.cornell.edu/onthemap/data/. Each year, a new release (v3, v4, v5,...) is released, which typically contains at least data on one additional year, and often additional data elements.
Early versions of the BDS are available at http://www.vrdc.cornell.edu/bds/. Versioning is by approximate date of release.