TIGER/Line Shapefile, 2008, nation, U.S., County and Equivalent
U.S. Department of Commerce, U.S. Census Bureau, Geography Division
The TIGER/Line Shapefiles are an extract of selected geographic and cartographic information from the Census MAF/TIGER database. The Census MAF/TIGER database represents a seamless national file with no overlaps or gaps between parts. However, each TIGER/Line Shapefile is designed to stand alone as an independent data set or the shapefiles can be combined to cover the whole nation.