The Dilemma: You know your sharks from your jets and your Rodgers from your Hammersteins. But what in God’s name is a commonwealth?

Materials Needed: a map of the U.S. and its territories. Just don’t call ‘em colonies!

People You Can Impress: geography buffs or any proud residents of four of our medium-sized, heavily accented states

The Quick Trick: There’re only four commonwealths, so just memorize ‘em, willya? If you can remember John, Paul, George, and Ringo, you can swing MA, PA, VA, and KY.

The Explanation:
There are fifty states in the U.S., but four of them—Pennsylvania, Kentucky, Virginia, and Massachusetts—officially call themselves commonwealths. And the difference between a commonwealth and a state is, well, nothing. Constitutionally speaking, they’re identical.

Understanding why these states chose the commonwealth moniker and continue to stick to it so proudly is a lot easier once you consider the history of those states. The original meaning of the word commonwealth was a nation or body governed by the people, not some king or tyrant. In fact, the time in British history during which Cromwell and Parliament ruled instead of a king is known as the Commonwealth Period. So when it came time for the American colonies to throw off the yokes of oppression and tea taxes and the excessive use of the letter u in words like colour, the three hotbeds of revolution—Massachusetts, Pennsylvania, and Virginia—were most eager to signal the difference in government. Perhaps remembering the Commonwealth Period, they declared themselves commonwealths. So what about Kentucky? Kentucky had once been merely a giant western county of Virginia (before that, it was called Transylvania). When it started doing its own thing in 1790, Kentucky kept the commonwealth status. Not to mention the whiskey.

But surprisingly enough, those four states aren’t the only ones in our happy American family that are commonwealths. Puerto Rico and the Northern Mariana Islands also go by the moniker. In this context, it means that they have certain rights under the U.S. Constitution and fall under our protection, but they don’t qualify for the full benefits of statehood—meaning they don’t get any senators and they also don’t get to eat deep-fried Twinkies, because they don’t get to have state fairs. (Kentucky, on the other hand, has a state fair each August, apparently unperturbed by the fact that it is not, technically, a state.)

State of Dissatisfaction
After the commonwealth of Virginia seceded from the Union in 1861, several northwestern Virginia counties went ahead and seceded from the seceders, choosing instead to stay in the Union. Those counties formed the state of West Virginia, feeling no compunction to keep the commonwealth label.