1929-1968 20thcentury activitépolitique africanamericanchildren africanamericancivilrightsworkers africanamericanyouth childrenandwar childsoldiers civilrightsmovements consolidationdelapaix enfantsetguerre enfantsetpaix enfantssoldats history jeunesse jeunesseetpaix martinluther mouvementsdejeunesse nonviolence peace-building politicalactivity politicalandsocialviewsking unitedstates youth youthandpeace youthmovements