Is pre-1990 historical block-level census data available online?

Question

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?

Answer 1

The National Historic Geographical Information System (nhgis.org) out of the University of Minnesota has census tract boundaries for the 1970, 2000, and 2010 censuses. They have census tracts that go back to 1910. They also have a wide variety of statistical information for each of the census years back to 1790.

Hope that helps!