When was traffic federation Zollverein established?

Zollverein, or The German Customs Union established in 1834 under Prussian leadership. It created a free-trade area throughout much of Germany and is often seen as an important step in German reunification. It was a coalition of German states formed to manage tariffs and economic policies within their territories. By 1866, the Zollverein included most of the German states. The foundation of the Zollverein was the first instance in history in which independent states had consummated a full economic union without the simultaneous creation of a political federation or union.