Search Results Use the search box below to revise your search, or start a new search. Studies (5) Variables Publications Your query returned 5 studies. Series results are grouped under the most relevant study. Ungroup series results to view all results. Sort by: Title A-Z Released/Updated Time Period Most Cited in ICPSR Bib. 1. Height of Free African Americans in Maryland, 1800-1864 (ICPSR 3422) Komlos, John 2. Philadelphia Social History Project: Pennsylvania Abolition Society and Society of Friends Manuscript Census Schedules, 1838, 1847, 1856 (ICPSR 3805) Hershberg, Theodore 3. Puerto Rico's Padrones, 1779-1802 (ICPSR 30262) Scarano, Francisco A.; Curtis, Katherine J. 4. Union Army Recruits in Black Regiments in the United States, 1862-1865 (ICPSR 9426) Metzer, Jacob; Margo, Robert A. 5. Union Army Recruits in Black Regiments in the United States, 1862-1865: [Instructional Materials] (ICPSR 3466) Oberly, James W.