He earned his Doctor of Philosophy degree in history from the University of Wisconsin–Madison, for a study of the life of George Perkins Marsh, an early geographer and conservationist.
He left active service with trench foot, and it was while recuperating in Somerset that his long association with England, later to become his adopted country, began.
In December 1944, he was reassigned to Army Intelligence and embarked on a mission to count toilets in German castles to ascertain how well each might support the occupation forces.
While taking part in the Intelligence Photographic Documentation Project – a never-completed mission to survey and catalogue the whole of western Europe's terrain and built environment – Lowenthal fell from his truck and fractured his wrist, which resulted in his being recalled to Washington in September 1945.
Other key texts of his in the field of historical geography include The Heritage Crusade and the Spoils of History (1996), and Passage du Temps sur le Paysage (2008).
[9] Landscape photographs taken by Lowenthal in the 1950s were included in a French exhibition at Le Pavillon Populaire in Montpellier, France, from 8 February to 16 April 2017 and accompanying book Notes sur l'asphalte, une Amérique mobile et précaire, 1950-1990.