When it collects data on the American population, the Census Bureau organizes that data according to a number of different geographies: states, counties, “Metropolitan Statistical Areas” or MSAs,” “Census Designated Places” or “CDPs,” Census tracts, block groups, and blocks.

The Bureau defines a Census tract as “a small, relatively permanent statistical subdivision of a county delineated by a local committee of census data users for the purpose of presenting data…designed to be relatively homogenous units with respect to population characteristics, economic status, and living conditions at the time of establishment, census tracts average about 4,000 inhabitants.”

Perhaps the key to this definition is that the Bureau aims to keep tracts at about 4,000 people.  Hence, if the net population of any area changes dramatically over the years, the Census tracts associated with that area are likely to change size and shape to accomodate these changes and stay within the “4,000 people” goal.

Trinity College is located in Census tract 5027. If you go here, you can see what Tract 5027 looks like relative to other nearby tracts in Hartford.  The horizontal line forming the southern border of 5027 is New Britain Avenue.  (This map comes from the fantastic site put out by the Hartford Public Library, HartfordInfo.  Be sure to check out this site in more detail!).  Want to know what Census tract you live in? Type in your address here.

Often, you will see a Census tract number as part of a much larger number, for example:


Refers to the state of Connecticut. In contrast, 08 would refer to Colorado.

Refers to Hartford County.  In contrast, 007 would refer to Middlesex County.

These preceding numbers come from the U.S. Federal Information Processing Standard, and are often referred to as “FIPS codes.”  You can find the entire list of FIPS codes here.