Hi-
I was using the 1970 block data for a project and it’s been great. I have been unable to locate any block maps for 1970 anywhere. Do you have a recommendations on how I can understand the block data I am analyzing? I am looking specifically at San Francisco County.
We don’t know of an existing general source of digital maps of 1970 block boundaries. The Census Bureau published a series of print volumes of 1970 block data that include maps. Many university libraries have copies of those volumes.
As it happens, though, we’ve already started on a project to create 1970 block boundary data for NHGIS, and we’re on track to publish our first release sometime this fall. Serendipitously, San Francisco is one of a handful of areas that we’ve already completed. We can share the data for San Francisco County in a preliminary file very soon; it just needs a couple finishing touches. I’ll report back here with a link when it’s ready, possibly early next week if not later today.
Hi there! Thanks so much. How lucky for me! Thanks so much.
You can now obtain our preliminary shapefile for 1970 blocks in San Francisco County at https://secure-assets.ipums.org/nhgis/blocks-1970/block_1970_06075.zip.
You’ll be required to log in to your IPUMS account to access the file. If you have any trouble downloading or opening it, please let us know.
This is wonderful. Thank you so much. It did exactly what we needed.
Hi there Jonathan. We were so excited about having the blocks data we are actually going to use it for comparing 1970 to 2020 block data. We were curious if you have a crosswalk of the blocks? Thanks!
We do not currently have a crosswalk from 1970 to 2020 census blocks. We have that as the deliverable for one of our grants, but we haven’t started on that work yet. Unfortunately, I don’t have a timeline for that work yet.
Sincerely,
Dave Van Riper
Thanks for letting me know! And thanks for all your great work.