Midwest Airlines, Frontier, and AirTran all tried to hub in Milwaukee. Today, no one does. There are some cities that have been tried and don’t quite work as hubs. America West used to hub in Columbus, for instance.
Old airline brands never seem to die. There’s another attempt to bring back Eastern Airlines. An airline using the People Express name operated again for a few months in 2014. And Pan Am is a name that just won’t go away.