1818-1895 1925-2013 1937-1986 19thcentury africanamericansinpopularculture bessie biography douglass essiemae europe exploitation frederick gayl head history isaac jones julien karaelizabeth khoikhoi moralandethicalaspects museumexhibits racerelations racisminmuseumexhibits sarah socialconditions unitedstates walker washington-williams women womenslaves