Cartographic Datasets from federal governmental agencies and private sites
US Geodata (USGS) - Here you can find DEMS's, DLG's and LULC (Land Use and Cover) files for the entire country in varying scales, and formats.
National Atlas of the United States data. Various map layers downloadable in an ESRI shapefile format that can be used in geographic information, desktop mapping, and computer-aided design systems. All map layers are compiled at a scale of 1:2,000,000 and cover the full geographic extent of the United States of America. - from USGS
Bureau of Transportation Statistics - The BTS Office of Geographic Information Services is a national resource for transportation spatial data and GIS in transportation (GIS-T) information.
National Wetlands Inventory - The National Wetlands Inventory (NWI) of the U.S. Fish and Wildlife Service produces information on the characteristics, extent, and status of the Nationâs wetlands and deepwater habitats.
CIA World Map Database - The map data itself consists of coastlines, rivers, lakes, international political boundaries, US state boundaries, and Canadian province boundaries. Note the boundaries predate the end of the cold war.[ftp-data]
GIS Data Depot - provides a large selection of geographic spatial data from various sources including international data. Most of the data is free to download, but you do have to pay if you want a cdrom.
Soil geographic databases
STATSGO - Soil maps for the State Soil Geographic (STATSGO) data base are made by generalizing the detailed soil survey data. The mapping scale for STATSGO map is 1:250,000 (with the exception of Alaska, which is 1:1,000,000). The level of mapping is designed to be used for broad planning and management uses covering state, regional, and multi-state areas.
SSURGO - Field mapping methods using national standards are used to construct the soil maps in the Soil Survey Geographic (SSURGO) data base. Mapping scales generally range from 1:12,000 to 1:63,360; SSURGO is the most detailed level of soil mapping done by the Natural Resources Conservation Service (NRCS). SSURGO digitizing duplicates the original soil survey maps. This level of mapping is designed for use by landowners, townships, and county natural resource planning and management.
Search engines for cartographic data
Federal Geospatial Data Clearinghouse - is a collection of over 50 spatial data servers, primarily in North America, that have digital geographic data primarily for use in Geographic Information Systems (GIS) image processing systems, or other modelling software. These data collections can be searched through the following interfaces based on their descriptions or metadata.