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 2018, 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 tool allows you to enter an address anywhere in the U.S., have it mapped for you, and get the latitude-longitude coordinates of the address. Referenced by our CAPS and Geocorr 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.
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). Updated annually. These are the source of gazetteer filetype in the MCDC data archive.