Differences between Commonwealth and State

Commonwealth and state

The terms commonwealth and state are both used to describe political communities, but their meanings vary depending on the context. In the United States, "commonwealth" is used in the official names of four states, but this designation has no legal impact on their status. Internationally, the term often refers to a voluntary association of sovereign nations, the most prominent example being the Commonwealth of Nations. A state, in the context of international law, is a self-governing political entity.

The word "commonwealth" dates to the 15th century and signifies a political community founded for the common good or "common well-being". It is derived from a loose translation of the Latin term *res publica*, from which the word "republic" also originates. During the American Revolution, some political writers preferred the term to "state" for its republican and anti-monarchical sentiment.

Comparison Table

Category	State	Commonwealth
Primary Meaning	A sovereign, self-governing political entity.	A political community founded for the common good; can also refer to a voluntary association of sovereign states.
Sovereignty	Possesses sovereignty over its territory and governance.	Varies by context. U.S. commonwealths that are states are sovereign; U.S. territories designated as commonwealths are not. Member nations of the Commonwealth of Nations are sovereign.
Legal Status in the U.S.	The standard political unit of the United States.	The official designation for four states (Kentucky, Massachusetts, Pennsylvania, and Virginia) with no legal distinction from other states. It is also the designation for two U.S. territories (Puerto Rico and the Northern Mariana Islands) which do not have the same rights as states.
International Example	Any sovereign country (e.g., France, Japan).	The Commonwealth of Nations, a voluntary association of 56 member states, mostly former British territories.
Governance	Governed by its own constitution and laws.	In the U.S. context, governed by a state constitution identical in authority to other states. In the international context, members of an association like the Commonwealth of Nations are self-governed.

Venn diagram comparing Differences between Commonwealth and State

In the United States

Four constituent states of the United States officially designate themselves as commonwealths: Kentucky, Massachusetts, Pennsylvania, and Virginia. This choice of term dates back to the 18th century and reflects the influence of English common law and a desire to emphasize that their governments were founded on the common consent of the people. Despite the different name, these four states are legally identical to the other 46 states and possess the same powers and responsibilities within the U.S. federal system.

The term is also used for two U.S. territories: Puerto Rico and the Northern Mariana Islands. In this context, "commonwealth" indicates an area that is self-governing under its own constitution. However, as unincorporated territories, their relationship with the United States is distinct from that of the states, and their residents do not have full voting representation in the U.S. Congress.

International context

Internationally, the most recognized use of the term is the Commonwealth of Nations. This is a voluntary political association of 56 member states, the majority of which are former territories of the British Empire. Membership is based on shared traditions and cooperation, and the organization has no formal constitution or bylaws. The members are sovereign states and their association within the Commonwealth does not diminish their independence. The Head of the Commonwealth is a symbolic position. Several sovereign nations, such as Australia and the Bahamas, also use "Commonwealth" in their official titles.