There are several factors, and it depends on a lot of individual circumstances. Some breweries were too small to compete against Twin City (or Milwaukee or St. Louis) breweries that were now shipping into their territories. Some families simply ran out of children willing to take over the business. And some counties went dry before the rest of the state. Those breweries (such as Bemidji) could technically still brew, but they would have had to ship their beer so far it would not have been worth it.