So an interesting fact some of you might not know, is that the Zollverein wasn't initially intended to be the pan-European economic union that it is today. In fact, it was originally created by the Kingdom of Prussia as an attempt to encourage German political unification.
Of course, when Prussia lost a few wars, and larger and larger empires such as the Austrian Empire and the Netherlands joined the customs union, all lobbying for their own industrial, mineral, and agricultural interests, then the Zollverein became a looser and looser, and less and less German entity. This was a gradual process of course, probably accelerated by some of the economic crises in the mid-late 19th century and the French ascendance.
But what if the original purpose of the Zollverein--to encourage a full economic union of German states and only members of the former German Confederation--had been successful?
Prussia was once famous for having a strong military, although its foreign policy on all fronts but the economic one, was quite weak in the 19th century, probably due to the lack of good ministers and diplomats. There was no "Prussian Metternich", no "Prussian Talleyrand" so to speak, certainly not in the late Victorian era.
How could Prussia have created its own "German Empire"?