All 50 states, the District of Columbia, and Puerto Rico are now available for download from the U.S. Census Bureau's 2010 TIGER/Line products web page.TIGER/Line Shapefiles
The technical documentation for the 2010 Census Redistricting [P.L. 94-171] TIGER/Line Shapefiles can be accessed here:
TIGERweb: A new tool from the Census Bureau's Geography Division that allows users to visualize the 2010 census geography. This tool includes legal and statistical areas with their geographic identifiers, as well as the transportation network, and hydrography layers in the TIGER database. In addition, it contains the 2010 Census population and housing unit counts for the various geographic entities.
Please call the Census Redistricting Data Office at (301) 763-4039 should you have any questions.