Geographic codes lookup provides convenient and definitive tables of commonly used geographic codes (mostly FIPS) organized by state for the U.S.
Geocorr (geographic correspondence engine), one of our oldest and most-used web applications, lets you generate geographic correspondence files showing how geographic areas overlap (e.g., how ZIP codes relate with counties or school districts). Geocorr 2014, the post-2010-census version, has current geography. Geocorr 2000 has post-2000-census geography, and Geocorr 1990 is still useful for the geography of the 1990s.
Circular area profiles (CAPS) ACS: Dynamic n-mile radius reports based on popular demographic data for any location in US. Uses an enhanced algorithm to improve the estimates for small radii using the same ACS data.
Google geomap: This handy tool from the folks at Google allows you to enter an address anywhere in the U.S. and have it mapped for you and provide the latitude-longitude coordinates of the address. Referenced by our CAPS applications.
Geographic glossary file 2014: the latest version of this geographic reference tool is linked from our Geocorr 2014 web application (see above). It provides background information on a wide array of geographic coverages. There are also earlier versions available.
Census Bureau map products: This page is more current than the previous link. Use this link to get to reference (i.e. base) maps for entities such as metro areas (CBSAs), PUMAs, UAs, census tracts, etc.
U.S. gazetteer files for congressional districts, places, counties, county subdivisions, census tracts, American Indian areas, school districts, state legislative districts, urban areas, and ZIP Code tabulation areas (ZCTAs), various vintages updated annually. These are the source of gazetteer filetype in the MCDC data archive.
Geographic area tallies: This is where you can find out how many areas of a certain type were used in the 2000 and 2010 censuses. For example, the number of census blocks, block groups, and census tracts by state with national totals.