OMG.
I'm embarrassed to say baseball jackets are a WI thing too. Well at least until the APhis started the windbreaker trend on my campus then EVERYONE followed suit including the sports teams. But heck, we gave the local sports-shop guy good advertising too running around in our burgundy windbreakers with the big-ass Alpha Phi letters on the back. He hung two of them in the window of his shop across the street from the union and had a stampede.
We wore them every day, everywhere. We'd get them two sizes too big and wear them over our parkas in January. You Michiganders have no imagination.