Rubuta ci gaba don wannan sakin layi - Guthe ya yi hijira zuwa Amurka a lokacin rani na 1892 don ya auri Clara Belle Ware (1867-1947), daga Grand Rapids, Michigan. Ma'aurata sun hadu a lokacin ziyarar Ware zuwa Jamus a 1890-91. A shekara ta 1893 ya sami matsayi a matsayin malamin kimiyyar lissafi a Jami'ar Michigan, kuma a 1900 an daukaka shi zuwa Mataimakin Farfesa. A cikin 1903, Guthe ya ɗauki matsayi a matsayin Mataimakin Masanin Kimiyya a sabon ofishin National Bureau of Standards da aka kafa a Washington, DC (yanzu Cibiyar Nazarin Kasa da Fasaha). A shekara ta 1905 ya karbi gayyatar zama Farfesa na Physics da Shugaban Ma'aikatar Physics a Jami'ar Iowa. Guthe ya kasance memba na juri na kyaututtuka a St. Louis Exposition
a 1904 kuma ya kasance mataimakin shugaban kungiyar Amurka don Ci gaban Kimiyya a 1908. A cikin 1909 Jami'ar Michigan ta nemi Guthe ya dawo a matsayin cikakken Farfesa a Sashen Physics, kuma ya koma Ann Arbor tare da danginsa matasa. A cikin 1912 an nada Guthe Dean na sabuwar Makarantar Digiri na biyu a Jami'ar Michigan.