How did the unification of Germany come about?

Initially, the unification of Germany began from the economic side, when the North German Confederation was created in the 1860s to conduct trade more profitably without the internal barriers that had existed in Germany for a long time. Subsequently, the main event was the defeat of the French in the Franco-Prussian war, which made it possible to get rid of the last external factor for the unification of Germany, the main force for which was the economically powerful and stable Prussia. That is, the unification actually took place on a voluntary basis with the use of force in relation to external enemy forces.