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What is Black Group Data?

Block groups are statistical divisions of census tracts used by the United States Census Bureau to present data and control block numbering. They are the smallest geographic unit for which the bureau publishes sample data. 

A block group typically covers a contiguous area. However, it is possible for block groups to consist of blocks that do not share a common boarder. The size of a block group can vary, yet generally they are defined to contain between 600-3,000 people. There is at least one block group in each census tract, and those within a census tract are given a unique code. However, block groups never cross state, county, or census tract boundaries. 


Tribal Block Groups: Tribal census tracts and tribal block groups are defined by federally recognized American Indian reservations or off-reservation trust land. These types of geographic divisions can cross state and county boundaries and may be completely different than the census tracts and block groups defined by the state and county. A single tribal block group is defined by a population less than 1,200. Populations over 1,200 result in multiple tribal block groups. 


Block Group Codes: Each block group within a census tract has a unique numeric code using the digits 0-9. This is used to differentiate between block groups, as well as provide insight to certain characteristics of the block group. A code beginning with a zero represents a block group that only contains water area. To distinguish a county-based block group from a tribal block group, tribal block groups use an alphabetic code of the characters A-K. (This excludes "I" which could be confused with the number "1".)

How to Access Block Group Data from American FactFinder

This series of 10 slides will give step-by-step instructions on how to pull block group data from American FactFinder's download center. A block group is the smallest geographical unit used by the US Census Bureau as depicted in the image above. This data can be downloaded as an Excel file. Block group data can also be downloaded as a TIGER shapefile to use with GIS. To learn more about TIGER shapefiles, visit this link.   Navigate between slides by using the arrows on either side of the image or swiping left or right on your device.

How to Pull Census Block Group Data from American FactFinder

This series of 10 slides will give step-by-step instructions on how to pull block group data from American FactFinder's download center. A block group is the smallest geographical unit used by the US Census Bureau as depicted in the image above. This data can be downloaded as an Excel file. Block group data can also be downloaded as a TIGER shapefile to use with GIS. To learn more about TIGER shapefiles, visit this link

Navigate between slides by using the arrows on either side of the image or swiping left or right on your device.  

Begin by visiting the United States Census Bureau homepage at census.gov.

Step One

Begin by visiting the United States Census Bureau homepage at census.gov.

Select the top tab labeled

Step Two

Select the top tab labeled "Data: Tools, Developers". This will give you a drop-down menu of options. Select "Data Tools & Apps". From there select the first option, "American FactFinder".

This will bring you to the American FactFinder homepage. Select

Step Three

This will bring you to the American FactFinder homepage. Select "Download Center". This will give you a drop-down with two options, "Tell Me More" and "Download Center". Select "Download Center".

Once the Download Center has opened, it will walk you through a series of steps. This begins with selecting one of two options. Select the first option,

Step Four

Once the Download Center has opened, it will walk you through a series of steps. This begins with selecting one of two options. Select the first option, "I know the dataset or table(s) that I want to download". Select next.

First select the program. From the drop-down menu select the American Community Survey. A second-option will appear. Block group data is available for 5-year estimates. Select the 5-year estimates for the year you are interested in. You may select more than one. For this demo, select 2015 ACS 5-year estimates. Once the dataset is highlighted, select

Step Five

First select the program. From the drop-down menu select the American Community Survey. A second option will appear. Block group data is available for 5-year estimates. Select the 5-year estimates for the year you are interested in. You may select more than one. For this demo, select 2015 ACS 5-year estimates. Once the dataset is highlighted, select "Add to Your Selections". Select next. 

You will now select the geographic units you are interested in. From the drop-down menu, select

Step Six

You will now select the geographic units you are interested in. From the drop-down menu, select "Block Group". 

Once

Step Seven

Once "Block Group" has been selected as the geographic unit, you will be asked to select a State and County. For this demo select Oregon as the state and Lane County as the county of interest. This will populate the available geographic areas according to the selections you made. In this case, one is available. Highlight the option "All Block Groups within Lane County, Oregon" and select "Add to Your Selections". 

You will now be given a list of all datasets available per your geographic selections. For this demo, we are provided with 342 tables. Select the tables you wish to download by checking the box next to the name of the dataset. For this demo we are interested in the total population per block group in Lane County. Select the table titled

Step Eight

You will now be given a list of all datasets available per your geographic selections. For this demo, we are provided with 342 tables. Select the tables you wish to download by checking the box next to the name of the dataset. For this demo we are interested in the total population per block group in Lane County. Select the table titled "Total Population" and select next. 

A popup window will appear. It will display the tables you have selected for download as well as give you two options. The first option is to include descriptive data element names. This should be automatically checked and is recommended to leave checked. The second option is to include geographic components (e.g., Urban, Rural, Statewide, etc.) in the download if available in the table. This may be helpful at times when available. For this demo we will leave this option unchecked. Select

Step Nine

A popup window will appear. It will display the tables you have selected for download as well as give you two options. The first option is to include descriptive data element names. This should be automatically checked and is recommended to leave checked. The second option is to include geographic components (e.g., Urban, Rural, Statewide, etc.) in the download if available in the table. This may be helpful at times when available. For this demo we will leave this option unchecked. Select "okay" to download the data. 

The data is downloaded as a zip file. Each table will include two Excel files. One contains the metadata for the table. The second contains the dataset. Open the dataset file. A portion of the table for population by block group in Lane County, Oregon is provided here. This data is now available for use!

Step Ten

The data is downloaded as a zip file. Each table will include two Excel files. One contains the metadata for the table. The second contains the dataset. Open the dataset file. A portion of the table for population by block group in Lane County, Oregon is provided here. This data is now available for use!

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