Search Results Use the search box below to revise your search, or start a new search. Studies (1) Variables Publications Your query returned 1 studies. Sort by: Title A-Z Released/Updated Time Period Most Cited in ICPSR Bib. 1. Census of Population, 1880 [United States]: Public Use Sample (1 in 1000 Preliminary Subsample) (ICPSR 9474) Ruggles, Steven; Menard, Russell R.