1935- 1961-1975 960 american art artcollectionsvogel artisticcollaboration bongo christo collectivememory conceptualart dorothy economicdevelopment exhibitions fon(africanpeople) gabon herbert jeanne-claude johngrider miller nationalism omar personalnarratives philosophy politicalcorruption politicsandgovernment privatecollections reconciliation socialaspects ubuntu(philosophy) vietnamwar