Thanks to Liang for these links.  I, too, have found FactFinder and DataFerrett to be less than intuitive.  Building on Liang’s message, in addition to ACS Alchemist, US Census also puts out a data retrieval tool that does a pretty good job of retrieving the 1, 3 and/or 5 year data sets.  Look at the links for the Summary File Retrieval Tool under “Tools for Using the ACS Summary File” at the following link:


The difference between something like ACS Alchemist or the Summary File Retrieval Tool is a matter of both task and personal preference.  For example, some of my tasks involve dealing with both the ACS Estimate and the Margin of Error (two different data columns), so I like the fact that the Summary File Retrieval tool can be easily set up to consolidate both of those pieces of data.  I also like the fact that the Summary File Retrieval Tool automatically loads the ACS table names and column definition in a Metadata tab, so you can easily turn to the documentation in the middle of your data assembly tasks.

That said, it does take some extra steps to get the data into a nice, clean format that plugs into a GIS; ACS Alchemist may handle a lot of those tasks on the back end.  So, it is a question of how one wants to access the data.  I would be interested in hearing from others what experience they’ve had with the Summary File Retrieval Tool.  Any thoughts?


Mike Greenwald

Michael J. Greenwald
Senior Transportation Planner
Lane Council of Governments
859 Willamette Street, Suite 500
Eugene, OR 97402
Tel:  541-682-6595
Fax:  541-682-4099

From: [] On Behalf Of Liang Long
Sent: Tuesday, October 23, 2012 11:55 AM
Subject: [CTPP] An Alternative to Access ACS 5-year Block Group Data


Hi, all

If you are frustrated by getting the ACS 5-year block group level data via Census Bureau ftpsite or DataFerrett, ACS Alchemist may be a good alternative.  

I just tested ACS Achemist that was developed by Azavea & Temple University and I think it's easy to use.  But keep in mind that only ACS 2005-2009 and ACS 2006-2010 data are available in the ACS Alchemist.  If you are looking for 1-year or 3-year data, you still need Census Bureau data access tools including American Fact finder and DataFerrett.

ACS Achemist is an open source tool that enables the extraction of ACS 2005-2009 and ACS 2006-2010 data  on different level of geographic aggregation, i.e., counties, county sub-division, tracts, blockgroups, etc.  .  The user interface is very straightforward and is a simple step-by-step process.  The thing I like most is that output is saved as the shapefile and you can process your data in the GIS.  The think I like least is that uses will have to create a variable file to define which data they want to get.  The sample of a variable file can be find in the readme document which is included in the software installation package, but I attached one here for your convenience.

Here is the link to the ACS Alchemist home page:

Here is the link to download the software package:


Liang Long
Cambridge Systematics, Inc.
4800 Hampden Lane
Suite 800
Bethesda, MD 20814
tel  301 347 9141
fax 301 347 0101
FHWA 202-366-6971