County-level data on full sample

Dear IPUMS community,

I am searching for county-level counts of the population by place of birth (BPL) for the years 1870, 1880, 1900, 1910, 1920, and 1930. What is the best way to get this data? Should I download the publicly available samples online, and how should weigh them to aggregate them to the county-level? Or should I apply for the full sample access of these years? Or is there a way to directly download the data at the county level?

Thank you very much.


NHGIS provides summary tables of census data, including population by birthplace at the county level. Alternatively, population by birthplace per county can be estimated using Census sample data available in IPUMS USA. The variable BPL (birthplace) can be used along with COUNTYICP to aggregate birthplace statistics at the county level. Nationally-representative population estimates can then be calculated using the person-level weight, PERWT. Total population by birthplace per county can also be calculated using the USA Complete Count files. Due to their large size, however, these files can be cumbersome to work with. The following are links to apply for access to these data: IPUMS NHGIS, IPUMS USA.