Federal Government, or federalism, a form of government whereby political power is divided between a central or national authority and smaller, locally autonomous units such as provinces or states, generally under the terms of a constitution. A federal government, or federation, is usually formed through the political union of two or more formerly independent states under one sovereign government that does not, in any case, arrogate the individual powers of those states. It is distinguished from a confederation, which is an alliance of independent countries that retain their respective autonomies, for joint action or cooperation on specific matters of mutual concern. In a federal nation, the acts of the central government may affect directly both the member state and the individual citizen, whereas in a confederation such action usually affects the member countries directly and the citizen only indirectly.
A federation is also distinguished from a so-called unitary system, in which the central government holds the principal power over administrative units that are virtually agencies of the central government. The United Kingdom, for example, has a unitary system of parliamentary government, and many ostensibly federal governments, notably totalitarian regimes with one political party, are in fact unitary systems. Generally speaking, distinctions between federal governments, confederations, and unitary systems of government are relative and not easily made. Countries that have essentially federal systems of government include the United States, Canada, Mexico, Australia, India, Malaysia, Switzerland, and Germany.
In a federal nation, definite powers are allotted to the central government. It has full sovereignty in relation to external affairs and is pre-eminent in respect to internal administration within its allotted powers. Notable examples of federations found in antiquity include the Delian League and the Achaean League, Hellenic unions generally considered among the earliest political attempts to achieve united or national strength without the sacrifice of local independence. Elements of federalism existed in the Roman Empire. During the Middle Ages, many leagues of states were formed for specific purposes, one of the best known being the Hanseatic League. During the Renaissance, the Union of Utrecht, an alliance formed in 1579 of seven provinces of the Netherlands, was in the nature of a federation and was the strongest Protestant force in Europe for about two centuries. Switzerland, which has historically been considered the prime example of successful confederation and, later, federation, began the process of the union in 1290 with perpetual-alliance treaties binding three cantons, or small territories. The number of cantons included in the treaties gradually increased and, with the exception of a brief period as a unitary nation under French influence, the confederation continued until 1848 when it was transformed into a federal government. The modern government of Germany was federal inform both during the empire, in spite of the disproportionate importance of Prussia after 1871, and during the Weimar Republic. After some experience as a confederation, the United States adopted the federal form of government in 1789, and the United States Constitution has been a model followed by many countries, especially in Latin America.