What's the Difference Between a State and a Commonwealth?

If you grew up in the United States, you probably have the 50-states song burned into some indelible part of your memory. (If you’re like me, it’s the same place where a song made up of 62 prepositions sung to the tune of “Yankee Doodle Dandy” and the entirety of Billy Joel’s “We Didn’t Start the Fire,” which for some inane reason I was forced to memorize for seventh grade Social Studies class, also live.) What was not taught to me in school, however, was the simple difference between a state and a commonwealth—and all of the nuances the term “commonwealth” encapsulates. Less Schoolhouse Rock, sure, but just as important.

Let’s get to the first definition of commonwealth. Pennsylvania, Massachusetts, Virginia, and Kentucky are all commonwealths. So what makes them different from the rest of the 50 states? Literally nothing. They are commonwealths simply because their state constitutions say they’re commonwealths. Turns out you can just slap on the term “commonwealth” to your name, like “The Commonwealth of Pennsylvania,” and you’re a commonwealth! Who knew. 

So why these states in particular? According to the Massachusetts state website, “In the era leading to 1780, a popular term for a whole body of people constituting a nation or state (the body politic) was the word ‘Commonwealth.’” Pennsylvania, Virginia, and Massachusetts all adopted constitutions between the years 1776 and 1780, so we can assume that calling yourself a “commonwealth” during that era was somewhat in vogue. Kentucky didn't call itself a commonwealth until its Third Constitution of 1850, so I guess they were just late to the party.

However, this version of “commonwealth” is clearly different than the commonwealth that is Puerto Rico, considering the above examples are states and Puerto Rico is not. Both Puerto Rico and the Northern Mariana Islands, a group of 22 islands in the western Pacific Ocean, are also commonwealths, but with different relationships with the United States than the states that happen to also call themselves commonwealths. According to Merriam Webster, they are territories that have “local autonomy” but are “voluntarily united with the United States.” Under this arrangement, Puerto Rico has political autonomy on local matters, such as elections, taxation, education, health, housing, and language, while the U.S. government controls more external-facing affairs like citizenship, immigration, customs, defense, currency, foreign trade, and diplomacy. Residents are U.S. citizens, but do not pay federal taxes and only have non-voting representatives in the U.S. Congress. They also cannot vote for president; residents of Puerto Rico have no votes in the Electoral College, while residents of the North Mariana Islands who have lived on the U.S. mainland can vote in the most recent state that they lived in. 

So, in short: “commonwealth” can mean something that is the exact same thing as a state, but also something that is decidedly not the same thing as a state. Cool, guys. Definitely makes sense. 

But wait! There’s more. All of these various versions of commonwealths should not be confused with the Commonwealth, with a capital C. The Commonwealth is made up a collection of countries formerly under British rule, as well as other countries who voluntarily opt into it (such as Mozambique, which was not a former British colony but decided to join in anyways). It’s composed of 53 countries and represents around 30% of the world’s population. (And if you'd like to learn more about the differences between the Great Britain, England, and the United Kingdom, I have just the thing for you.)

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