One image is worth a thousand words:
The first unified German nation-state since the Peace of Westphalia.
The good: Up to late 1888 there was very little tension with neighbouring states as Kaiser Friedrich Wilhelm, Kaiser Friedrich III (whose reign was far to short anyway) and Chancellor Bismarck did not pursue aggressive foreign policies after unification. The unification of Germany also lead to massive industrialisation and modernisation and gave us the Zeppelin.
The bad: Only one good, effective Emperor, his liberal son… I am repeating myself.
The ugly: We all know (we do, don’t we?) what happened in 1914.