What if the upper midwestern USA develops differently than OTL
Here's my scenario. Duluth and Superior diversify their economies in the early 1910s and weather the economic storm that destroys their once promising growth. Duluth has a population of 300K and superior around 150K and have a metro population of around 2 million.
Minneapolis and Saint Paul put an end to their rivalry and decide to merge and become one buroughed out city, a la New York City. Minneapolis is split into 5 boroughs and Saint Paul 4. The combined city then becomes the new city of Minnesota City, MN. Urban population: 800K. Most populated buroughs: New Warsaw (Present Day Northeast Minneapolis), North Mexico (Present day West Side of Saint Paul), Calhoun (Present Day Uptown) and Battle Creek (Present Day east side of Saint Paul) Metro population: 6M. The central new business district is situated between the former downtowns of both cities, now known as the boroughs of the arts-infused Minneapolis Heights and the old money filled borough of Old Saint Paul.
With the gas crisis which ensues during World War 2, Milwaukee becomes a secondary hub for vehicle production. Motorcycles become very big in the USA as a means for transportation since gas prices are at an equivalent 6$ a gallon during the Depression. Sales of the Model T fall sharply and Ford purchases the neighboring Detroit Motorcycle Company to compete with Milwaukee's Harley-Davidson.
The Detroit Motorcycle Company, introduces some small displacement, continuously variable transmission motorcycles which are considered these days to be ahead of its time. The Detroit Motorcycle Company then relocates to Grand Rapids and becomes Grand Rapids Motor Company. The small motorcycles enjoy some modest success, especially the 3 wheelers due to their better handling in the ice and snow of the Upper Midwest. They're considered niche products and kids toys throughout the life of the product but are still sought after because of their great gas mileage.
Italian motorcycle makers Piaggio introduces their own small displacement, CVT motorcycles with step through frames after WW2 is over. The popularity and comfort of the step through frames of the Italian motorcycles spell the end for the stand-over frame style of the GRMC. Forced to adjust to market forces Ford panics and spins off the GRMC into their own company. The GRMC then decides to introduce their own step-through style of motorcycles. The "Gremmics" as they are colloquially known as, recover their market share and become big hits in urban areas such as Minnesota City, New York City, Chicago, Boston and Kansas City.
General Mills spins off its consumer foods branch into the Des Moines Grain Company, which spurs a huge economic development in Des Moines. Des Moines has a population of 300K and a metro pop of 1.3M.
Rochester, MN is spared the tornado that destroyed the town in 1883. However, the need for a new Rochester area hospital is still felt after a rash of farm related injuries strike the Olmstead County, MN area and there are no hospitals around to treat the injured. The Mayo Brothers build their clinic, which trains some of the best doctors in the world 30 years later during WW1 and becomes a force in the medical community during WW2. It develops identically to OTL, although with a 20 year lag since there's no tornado which turns the city into rubble.