20thcentury africa africanamericancivilrightsworkers africanamericans africanamericanstudies americanhistory:c1800toc1900 americanhistory:fromc1900- architecture blackstudies c1800toc1900 citizenship civilrights civilrightsmovements documentaries emancipation ethnicstudies general histor history peopleofcolor photoessays photographs:collections photography pictorialworks racerelations slavery usa