The Milwaukee Road's Chicago-Twin Cities Hiawatha proved so popular that longer trains were needed, beyond the ability of the class A 4-4-2s to handle. In 1938 the American Locomotive Company erected six class F7 4-6-4s to take over the service. No. 100 appears in this ALCo builder's photo. The F7s retained their streamlined shroud, designed by Otto Kuhler, to the early end of their service life in 1949-51.