Historical federations are political entities formed by the union of multiple states or regions that maintain some degree of autonomy while being governed by a central authority. Examples include the United States after the Constitution was ratified in 1788 and the German Empire, which unified various German states in 1871. These federations often arise to promote unity, stability, and cooperation among diverse groups. The structure of historical federations typically involves a division of powers between the central government and member states. This allows for local governance on certain issues while ensuring a cohesive national policy. The Swiss Confederation and the Australian Federation are other notable examples, showcasing how federations can adapt to different cultural and political contexts.