In 1972, he was a leader in the Trail of Broken Treaties, a caravan to Washington, DC to convince the Bureau of Indian Affairs to honor federal treaties with Native American tribes.
ɪn nˈaɪntiːnhˈʌndɹɪd sˈɛvənti tˈuː, hiː wʌzɐ lˈiːdɚɹ ɪnðə tɹˈeɪl ʌv bɹˈoʊkən tɹˈiːɾiz, ɐ kˈæɹɐvˌæn tə wˈɑːʃɪŋtən, dˌiːsˈiː tə kənvˈɪns ðə bjˈʊɹɹoʊ ʌv ˈɪndiən ɐfˈɛɹz tʊ ˈɑːnɚ fˈɛdɚɹəl tɹˈiːɾiz wɪð nˈeɪɾɪv ɐmˈɛɹɪkən tɹˈaɪbz.