fɹʌm nˈaɪntiːnhˈʌndɹɪd θˈɜːɾi ˈeɪt tʊ æt lˈiːst nˈaɪntiːnhˈʌndɹɪd fˈoːɹɾi, kˈɜːtʃhɔf wʌzɐ mˈɪlɪtənt əvə ɡɹˈuːp kˈɔːld ðə ɡɹˈuːpoʊ də tɹˈæbɐdʒˌædoːɹz mˈɑːɹksɪstəz dʒˌiːˌɛmtˈiː ɪn mˈɛksɪkˌoʊ.
From 1938 to at least 1940, Kirchhoff was a militant of a group called the Grupo de Trabajadores Marxistas (GMT) in Mexico.