Hello,
I have noticed that shapefiles for county subdivisions exist for 1980 onwards but not before. Old election results were typically reported at this level, which makes it a bit challenging to integrate to other census boundaries for analyses.
I was curious if there have been any plans to create these, taking into account the varied history of each state’s MCDs or CCDs. If there is no plan, are there any recommendations on finding similar boundary shapefiles?
Thank you
Dear Simon,
We currently have no plans to create historical MCDs or CCDs for IPUMS NHGIS. As you note, each state’s historical versions of these units vary dramatically. Finding the requisite maps that align with the footprints of these units for decennial censuses is a substantial amount of work.
We’ve done some work creating historical point-based geographic files of places, and we have a similar dataset for county subdivisions. But we haven’t yet assigned them geographic codes for linking with historical census data. We have names on those historical point files and could share them with you as is if you’d like.
Sincerely,
Dave Van Riper
IPUMS
Dear Dave,
Thank you very much for the kind and quick response. That is unfortunate to hear, but quite understandable given the amount of work and time that would be needed.
Thank you for the offer of sharing the historical point-based name file. That would be greatly appreciated if you can share them. Looking forward to hearing from you again and have a great weekend!
Sincerely,
Simon
Dear Simon,
If you send an email to NHGIS@umn.edu with your contact information, I will get the data to you.
Sincerely,
Dave