Via the Kelly Lab Blog, the Berkeley/Penn Urban & Environmental Modeler’s Datakit has an enormous set of vector and raster data for the contiguous 48 US states:
Vector:
• Municipal, county, metropolitan area, and state boundaries, as assembled from the US Census Bureau’s 1990 and 2000 TIGER data.
• 1990 and 2000 census block and census tract boundaries and selected attributes, including net housing and population densities.
• Highway, railroad, and urban rail transit networks; and air and seaport locations as assembled from the U.S. Department of Transportation’s Bureau of Transportation Statistics.
• Locations of major employment centers and employment data for 1994 and 2003.
• Boundaries of all federal lands, including national parks and monuments, national forests, Bureau of Land Management lands, and military facilities.
• Locations of all major water bodies including rivers, streams, lakes, and reservoirs.
Raster:
• Municipal, county, metropolitan area, and state boundaries.
• Census block and census tract boundaries and selected attributes, including net housing and population densities (blocks) and population, housing, and demographic data (tracts).
• Boundaries of all federal lands, including national parks and monuments, national forests, Bureau of Land Management lands, and military facilities.
• Elevation and slope data generated from the National Elevation Dataset (NED).
• Comprehensive land cover data for 1992 and 2001 from the U.S. Geological Survey, including agriculture, forest, pasture, urban, and wetland locations.
• Locations of all major water body polygons, including lakes and reservoirs.
• Locations of lacustrine, palustrine, and riverine wetlands from the National Wetlands Inventory.
Data is in Lambert Conformal Conic NAD83 projection.