In April 1945 he seized the chance of leading an investigative team into Germany searching for head of Nazi Party publishing
Max Amann. On this assignment he also came to
Marburg, where he realized his true calling would be to revive the German university system. He let himself be transferred to the Education and Religious Affairs Section of
OMGUS (Office of Military Government, U.S. for Germany), usually simply called the Military Government. At first, he joined Major General Morrison C. Stayer on an inspection tour of medical schools in July 1945. These medical schools turned out to be the loophole for the conservation of German universities as a whole which according to standing orders should have been completely closed down. Soon Hartshorne was recognized to be the most knowledgeable specialist on higher education in Germany. He was directly in charge of
Heidelberg and
Marburg. Using these two universities as test cases Hartshorne developed the
standard operating procedure for the
denazification and reopening of all seven universities in the U.S. zone, i.e. he had to select the ones capable of opening –
Giessen was closed down in the process – and planned and supervised the process of opening. Moreover, he was also involved in shaping university policy in general. Before the local planning committees began to function he had to drive around the country never staying for more than four days at any one place. After the Land
Greater Hesse had been proclaimed Hartshorne became in charge of higher education there (universities at
Frankfurt, Giessen, and Marburg) in October. He also succeeded in convincing his wife to come to Germany. She arrived with their three children in June 1946. ==Early death==