Census Data

Downloading Census Data

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While Census data is one of the most basic and valuable data sets available obtaining the particular attribute data you need can be a daunting task. Navigating the Census web site is rarely a quick process...

In Census data the nation is broken down into ever smaller geographic units: States are subdivided into Counties which are further divided into Tracts which are broken into Block Groups which are made up of Blocks. In an urban area a census 'Block' is literally a city block. However in rural areas a 'Block' may be quite large. In no case does a census unit cross more than one larger unit (that is, you never have a Block that is in two Block Groups or a Block Group that crosses into two Tracts, etc.). A group of Blocks makes up a Block Group, a group of Block Groups makes up a Tract, etc.

The two main data files that get used the most are Summary File 1 and Summary File 3.

Summary File 1 is derived from a 100% count (a full sample of every person) and contains information down to the block level. Summary File 1 contains information on population, housing units, age, gender, household relationships, etc. Note that Summary File 1 does not contain detailed income data.

Summary File 3 is derived from a sampled dataset (approximately 1/6th of the total population) and is thus less accurate than Summary File 1. It also only goes to the Block Group level. Summary File 3 contains more detailed population and housing data (place of birth, education, employment, income, housing value, year built, etc.).

GIS files of key data attributes (such as population and housing units) is often available, however it is difficult to find the full Summary Files (Summary File 3 contains hundreds of attributes). For this level of detail you will probably need to consult the census web site ( http://www.census.gov/ or http://www.census.gov/main/www/cen2000.html ).

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If you need the data for multiple fields and/or multiple Blocks/Block groups/Tract you can use the American Fact Finder pages:

http://factfinder.census.gov/servlet/DatasetMainPageServlet?_ds_name=DEC_2000_SF3_U&_program=DEC&_lang=en

(Be sure you have the 2000 Census tab selected at the top of the page - not the 1990 Census tab)

From this page, click on the the Radio button beside:

Census Summary File 1

Census Summary File 2

Census Summary File 3

etc.

Having selected which Census File you want to get data from, click on Detailed Tables

For Summary File 3 (as an example) you then have the option of choosing a Geographic Type (State, County, Tract, etc.) and location. So you could choose:

Geographic Type = Block Group

State = Washington

County = Whatcom County

Tract = Census Tract 1

Having selected Tract 1 you can then choose one or more (or All) Block Groups

Use the Add button to add the desired Block Groups to your Current Geography Selection list

You can return to the Census Tract selection to choose other Tracts and add more Block Groups

When you have your area(s) selected, click Next

You now need to select specific Tables for data (note that there are hundreds to choose from...)

Again, choose desired table(s) and use the Add button to add them to the list of Current Table Selections

You can also use the Ctrl or Shift keys to select multiple tables

When you have selected your table(s), Click on Show Result

Your requested data is displayed on a web page

To download this data, Choose Download from the Print/Download drop-down menu:

Choose the type of file format you prefer - note that there are multiple types of Excel file... (recommended: one of the 'Database compatible' options such as the Excel or Comma delimited txt)

Recommended: Check Include descriptive data element names

Click OK

Note that if you have multiple tables selected some formats will combine these into multiple worksheet pages within a single Excel file.

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