After returning to New York after World War I, Dehn felt that it was not the right place for him to regain his artistic passion. So, like many great artists, he packed up his supplies and made his way to Europe looking for inspiration. He spent a lot of his time in 1920s Vienna and Berlin, taking in the glory of the Weimar Republic. It was even in Vienna that he met his first wife, Mura Ziperovitch, an 18-year-old Russian dancer.
He returned to Europe following his marriage to his second wife, Virginia, where he collaborated with several print artists in Spain, Paris, and Majorca. And, in his final years, he continued to travel following his retirement from the National Academy of Design, looking for inspiration wherever he could.