What is the difference between a 'commonwealth' and a 'state'?

Commonwealth vs. State

Before you even begin to discuss the concepts and differences between these designations, you have to first determine where you are located. So, where are you talking about? Commonwealths and States, in domestic law, are pretty much treated the same. So much so that one could say there is no practical difference. As a basic rule, in the United States of America, commonwealths and states are treated the same under the U. S. Constitution.

Like the other comments following, it depends on what kind of commonwealth you're talking about; some consider Puerto Rico a commonwealth (which has some benefits of federal assistance, but restricted voting rights, etc). However, if you're asking about Virginia, Kentucky, Massachusetts, or Pennsylvania (the four "states" in the US that call themselves a commonwealth), in a commonwealth landowners do not possess mineral or oil rights to their land. They don't actually own their land but own its use. However this does not significantly differentiate their structure or self-government in any way from other states in the Union. Other FAQ Framers have offered these opinions:

• A state is a sovereign entity. According to my dictionary a commonwealth is a state with self government, in other words a democracy or republic.

• When I was very young growing up in the Commonwealth of Massachusetts my dad taught me that living in a Commonwealth meant that sovereignty was with the people by definition, not by grant of the federal government. Such sovereignty of the people may de facto be true with other states, but those who call themselves states have not by definition recognized that sovereignty of the people is in their very identity as have commonwealths. For all other states, such sovereignty is only voluntarily chosen (though guaranteed by the US Constitution. Unlike states, commonwealths do not need to resort to the federal government to guarantee the peoples' sovereignty. States must resort to the federal government for such guarantees.

The above statement simply is not true. Studying the constitutions of most states you will find similar wording regarding the states identity or "sovereignty". To the federal government all states are created equal. The differences come about through actions of the states (or in VA, MA, PA and KY the commonwealth). Relative to the US there is NO difference between a state and a commonwealth although there are certainly differences in how each state is governed.