Literacy by race, county-level data

Do literacy or educational attainment data by race exist at the county-level for 1940 and 1950? I’m looking for US data. I did not see it reported in the NHGIS tables, but was hoping that the relevant pages from the Census volumes were at least available somewhere online in PDF format. I thought I would ask before continuing my search.

I also didn’t turn up this information in NHGIS or in the published Census volumes (or when searching In 1940, county-level identifiers are available in the public use microdata files, so you could create the table yourself using IPUMS USA. However, beginning in 1950 counties are no longer identified in the public use microdata, and therefore only available on the IPUMS versions of the data when they can be inferred from other geographic units.