Petschauer arrived in the U.S. in 1957 at age 17 and almost immediately set out to continue the education he had started in Europe and obtained B.A., M.A., and Ph.D. degrees in European and Russian History at New York University.  He taught European history at Appalachian State University in Boone, NC from 1968-2006.  In addition, he led several programs, including the university's faculty and staff development center and headed Appalachian’s Faculty Senate and the UNC system’s Faculty Assembly.

He taught at several other institutions, including for ten years in the S.C. Governors School at the College of Charleston, for seven years in the Summer Institute at Palacki University, Olomouc, the Czech Republic, and one semester at North Ossetian State University in Vladikavkaz, North Ossetia.

He published and presented widely both nationally and internationally. His Der Vater und die SS [The Father and the SS, 2007] is now out of print, but it explored his relationship with his father. The struggles during the 20th century of the women in Italy and Germany whom he calls his mothers, is a historical exploration of their courage, steadfastness and care for their families and him. It is titled In the Face of Evil (2014) His novel, A Perfect Portrait (2016), explores the joys and difficulties of a very talented young woman in the eighteenth-century Germanies to become a professional artist. Last year's book (2019) features a selection of his most recent poems. They range from the personal to the political. This year (2020) he made available An Immigrant in the 1960s. Finding Hope and Success in New York City. The title says it all.

He received a Dr. h. c. from Appalachian in May 2014.