In 1937, Berghult was elected to serve as the 26th
mayor of Duluth, Minnesota until 1941. At the age of 31, Berghult was the youngest mayor of a U.S. city with a population larger than 100,000, as well as the first native-born mayor of
Duluth, Minnesota. Berghult was credited with secured government funding for the
Blatnik Bridge and working to beautify the city's public land as mayor, in addition to revising the city's debt structure and beginning several health and work programs for its citizens. Berghult was preceded by
Samuel F. Snively and succeeded by
Edward H. Hatch. Following his tenure as mayor, Berghult joined the
United States Navy, earning recognition for his service at Normandy Beach and in Norway. He retired as a commander. ==Personal life and death==