I'm looking for historical block-level data for Chicago.
According to this Census bureau document, historical block-level census data exists for major cities going back to 1960, and even back to 1940 (though only for housing statistics.)
Only 1990 - 2010 is available on the census website.
Do digital copies of historical census block boundaries and stats exist? Are they available anywhere?
If not, where are the analogue versions of this data stored? And what is the most granular level of historical census data that is available digitally?