Steam billows dramatically from a towering Great Northern Railway grain elevator complex in Superior, Wisconsin — this early color-lithograph postcard from 1927 captures the raw industrial muscle of the Great Lakes grain trade at its interwar zenith, when Superior and Duluth together formed the world's largest grain-shipping port, funneling the harvest of the northern Great Plains east to the Atlantic. The massive tiered wooden elevator dominates the frame against a pastel sky, freight cars idling on the tracks below. On the reverse, a traveler — writing from Detroit on May 9, 1927 — scribbles a note to Mrs. John Merren at 329 Clarence Ave., Toledo, Ohio: "Just a few lines to let you know I am well and hope you are the same. Loaded ore at Duluth and are now on our way to Conneaut, O." The "LET'S GO CITIZENS MILITARY TRAINING CAMPS" machine slogan cancel lends a patriotic postwar flavor to this maritime-industrial snapshot, and the sender adds a self-deprecating P.S.: "I received your letter — I forgot to mail this coming down."