Fredrickson, an amateur photographer, began his 39-year career with the Northern Pacific in 1943. He took exceptional photographs throughout that time depicting the last glories of the steam era as coal-fired locomotives were replaced by diesel engines in the 1940s and 1950s. His photos and yarns tell of the NP's engines, depots, diners, cabooses, sidings, yards, shops, bridges, and tunnels.