I can download 2009 5-year ACS CBG data (eg B25003) for Miami-Dade county FL from IPUMS (yay!), but I cannot seem to access CBG-level ACS data from the Census website directly (FTP, API, etc.) until 2013. Do you know why not? How do you get the data?
The first set of ACS block-group data that the Bureau makes available via data.census.gov or its API is the 2013 5-year data. This doc explains that the pre-2013 BG data are available only in the summary file. To my knowledge, the situation hasn’t changed, except that American FactFinder has been replaced by data.census.gov.
You should be able to find block-group data back to 2005-2009 via the summary files here, which are the source for the NHGIS data.
Thanks for the fast response!
Yes, I looked at the summary files in the link you provided. The data are there for most counties. Inexplicably, however, a number of them (including Miami-Dade 12086) are only 318 bytes and just link to zip folders with empty files. NHGIS does seem to have the data though.
School of Politics and Global Studies
Arizona State University
I’m not sure exactly where you’re looking. Our source for 2009 5-year block group data for Miami-Dade would have been the file named
Florida_Tracts_Block_Groups_Only.zip at this location: Index of /programs-surveys/acs/summary_file/2009/data/5_year_by_state .
When I open the Florida zip file in the link you indicate, it creates a folder: “Florida_Tracts_Block_Groups_Only”. Inside the folder are ‘m’ and ‘e’ .txt files for each county FIPS. Most of the files have data in them. Some, however, e.g., m20095fl0086000.txt and e20095fl0086000.txt are empty files with zero bytes.
Ok, I think I see what I have been doing wrong. It has been a while since I’ve used these files and I forgot how they were organized! Sorry about the confusion.