Where can I find county-level land area?

Question

I'm looking for U.S. county-level land area (sq. miles) per 1990's. The U.S. Census provides gazetteer files for 1990, 2000, and 2010. I need data from 1950-1980. Where can I find this data?

This is what the gaetteer files look like:

    fips land_sqmi
   <chr>     <dbl>
 1 01001   594.436
 2 01003  1589.784
 3 01005   884.876
 4 01007   622.582
 5 01009   644.776
 6 01011   622.805
 7 01013   776.829
 8 01015   605.868
 9 01017   596.531
10 01019   553.700

Answer 1

Maybe NHGIS?
They have historic county level data back to the 1700's; you can see the data they offer here.