This package contains census linkage crosswalks for all US censuses 1850-1940. The linkage method is described in the README. The package also includes the code needed to create these links from the restricted IPUMS-Ancestry.com data.The crosswalks are based on the histid variable provided by IPUMS, and can be merged with the unrestricted IPUMS-USA data using that.The data of V2 are identical to those of V1. The only difference between the versions are some inconsequential edits to the README.The V3 data add the strict links and the code necessary to create them.

This package contains three sets of crosswalks (and the code to create them) for use with the complete-count census data provided by IPUMS. Each crosswalk links observations in those data sets to variables that can be created only by using the restricted IPUMS-Ancestry.com data. The three sets of crosswalks are as follows, and all are based on the histid variable: lengths of individuals' first and last names; commonness of individuals' first and last names; and imputed occ1950 codes for individuals currently with the code 979 ("Not Yet Classified").V2 is identical to V1 except for code/Execute.sh