This paper presents methods to assign contemporaneous geographic variables to recently recovered historical tax data. We explore various approaches to assign census tract variables to address-level data from the Internal Revenue Service (IRS) from the 1960s-1980s, with the goal of documenting this extraordinary data resource and preparing the files for spatial analyses and linkage to other contemporaneous data. Our efforts to associate mailing addresses with their contemporaneous census tracts were complicated by the changing nature of census tracts, technical limitations on how restricted data can be accessed and transformed, and the lack of year-specific street maps overlayed with year-specific census tract boundaries. We present three methods for assigning contemporaneous census tracts to historical records, evaluate the results, and conclude with recommendations and limitations.