The "Local Area Unemployment Statistics" Program (LAUS) produces employment and unemployment estimates for states, counties, cities with over 25,000 residents, and other labor market areas. LAUS unemployment rates are designed to be consistent with unemployment rates from the Current Population Survey, and they tend to be lower than unemployment rates from decennial censuses or the American Community Survey.
For the full range of available LAUS statistics, see:
http://stats.bls.gov/lau/
County Unemployment Rates, 1998-2007 (Excel file)
County Unemployment Rates, 1998-2007 (pdf file)
County Labor Force, 1998-2007 (Excel file)
County Labor Force, 1998-2007 (pdf file)
County Employment, 1998-2007 (Excel file)
County Employment, 1998-2007 (pdf file)
County Unemployment, 1998-2007 (Excel file)
County Unemployment, 1998-2007 (pdf file)
Updated February 26, 2009