States of the German Empire

The German Empire consisted originally of 27, and later (as of 1876) 26 constituent states, the largest of which was Prussia. These states, or Staaten (or Bundesstaaten, i.e. federal states, a name derived from the previous North German Confederation; they became known as Länder during the Weimar Republic) each had votes in the Bundesrat, which gave them representation at a federal level.

Several of these states had gained sovereignty following the dissolution of the Holy Roman Empire. Others were created as sovereign states after the Congress of Vienna in 1815. Territories were not necessarily contiguous, such as Bavaria, or Oldenburg—many existed in several parts (enclaves and exclaves), as a result of historical acquisitions, or, in several cases, divisions of the ruling family trees.

Different from the above-mentioned monarchies these city-states were constitutionally organised as republics.

Different from all other aforementioned constituent states, this region, comprising territory ceded by France in 1871, was first administered by the central government, growing later into a republic of restricted autonomy only, with an elected state parliament of its own as of 1912.

...
Wikipedia