Answer:
The Congress of Vienna, which lasted from 1814-1815, resulted in Confederation of German state(s) being officially recognized.
Explanation:
After the fall of Napoleon and the Congress of Vienna it was decided that a Confederation of German States, exactly 39 of them will be created. The main role in the confederation was played by Austria, but it was more than obvious that Prussia was a force to be recognized in that period. The creation of this Confederation was just one step towards the final unification of Germany.