If you want the actual data sources used by the paper, read the paper. I'm not trying to replicate an academic's source-finding, that would take months. I'm try

If you want the actual data sources used by the paper, read the paper. I'm not trying to replicate an academic's source-finding, that would take months. I'm trying to quickly demonstrate that the US was a thoroughly bureaucratic nation by 1920, not some kind of backwater where we have to guess and infer demographics.