Geography is at the heart of all Census Bureau data. All of our data sets pertain to very specific geographies that embody very specific geographic concepts. Although we try to make using our API as intuitive as possible, the greater your understanding of these concepts, the more powerful you become as a developer using these data.
Every query must include a geography, and this API supports both FIPS and GNIS geography codes.
To query the API your request URL query string must include a for argument which defines the geography level and FIPS code(s).
will find the total population for the state of California.
The "for" argument may include additional FIPS codes, separated by a comma.
will find the total population for the states of California and Maryland.
In some cases you must also include an in argument to fully qualify the geography.
will find the total population for Alameda County in the state of California.
Geocoding and Census Geographic Relationship Files
This is a collection of services and resources to help you with geocoding tasks and geographic relationships over time.
Understanding Geographic Relationships: Counties, Places, Tracts and More
Geography is at the center of taking a census. We do not just count people; we count people where they live… Read More.
Understanding Geographic Relationships: American Indian Areas
Part two in the Understanding Geographic Relationships series focuses on relationships that exist between different types of American Indian Areas. Part one in this series provided an overview of how Census Bureau geographies relate to one another.