U.S. Census Information

The Census has it’s own geography which largely ignores locally designated boundaries. If you need Census data for a specific neighborhood, community planning area, ward or other locally designated area you will need to determine what Census Tracts, Block Groups and Blocks best match up with your neighborhood boundaries in order to find the demographic statistics on the area. These boundaries may not match up exactly with the official boundaries of your community, but using street maps and Census Tract & Block maps you will be able to define an area that will work best for your research.

If you need just a basic snapshot data for a neighborhood or ward, this information is already available through The City of St. Louis. However if you need more detailed statistics or data prior to 2000 continue to the information below.

The most difficult part of defining your Census geography is figuring out how Census designated geographies overlay with the streets and neighborhoods we know from everyday life.

You will need to determine what Census Tracts, Block Groups and Blocks best match up with your community to find the Census Data you need. These boundaries may not match up exactly with the official boundaries of your community, but using street maps and Census Tract & Block maps you will be able to define an area that will work best for your research.

The Mapping & Graphics Division of the City of St. Louis Planning & Urban Design Agency has created detailed neighborhood and ward maps that will help you identify the generally accepted street boundaries for your neighborhood or ward.

For detailed street maps use a web based mapping tool such as Yahoo! Maps or Google Maps.

The quickest way to identify Census Tract and recent Census Block Group boundaries is to use Social Explorer's Mapping function. Social Explorer includes Census Tract boundaries for every available year back to 1940 and Census Block Group Boundaries back to 1990. Social Explorer is also an excellent way to quickly compare tract boundaries (and data) over time.

For detailed online Census Tract, Block Group & Block information for 1990, 2000 and 2010, you can use the Census Bureau Reference Maps in PDF. These PDF Block Maps are the most detailed maps available of Census geography. For earlier years, look for the maps in the Census Tract and Block volumes. (Maps are usually included in a back book pocket, or a separate folio shelved next to the volume.) 

Don’t forget! Census tract numbers & boundaries may change over time. Check all your Census years before making a final decision on Community boundaries. Remember, the farther back in time you go, the larger your Census Tracts are likely to be.

The Census Tract Tool Comparison includes the pros and cons of the three major tools for identifying census tract boundaries.