The United States of America is 234 years old today. In honor of that, we're going to challenge your brain's knowledge of the USA!

Don't worry. I'll start slow. Before any kind of exercise you need to stretch, don't you?

Start by imagining that Puerto Rico becomes the 51st state. According to the Flag Act of 1818, a new flag containing 51 stars would be released on the following July 4th.

What exactly would the US flag look like? Skip Garibaldi has examined our past flags, and used that knowledge to work out what the US flag would look like with up to 100 stars. He also discovered that we'll be faced with a quandry if we ever have 69 or 87 states.

The adoption of the Declaration of Independence on July 4th, 1776 is, of course, why we celebrate it as Independence Day.

The late Martin Gardner has actually managed to turn the first sentences of the Declaration of Indpendence into a magic trick, with a little help from Martin Kruskal.

We're passed the warm-up, and we're going to start with the big challenges. Sporcle is curious to know how many signers of the Declaration of Independence you can name in 10 minutes. Mental Floss, on the other hand, wants to know if you can identify the states that some of the lesser known Declaration of Independence signers were representing.

If you've read this far thinking, “Would the Founding Fathers really support celebrating Independence Day with these sorts of brain challenges?”, I'd like to think at least one would support this approach: Ben Franklin. He loved magic squares! A little over 4 years ago, the Sunday Times even posted Ben Franklin's Magic Square Challenge, whose goal was to complete this square so that it totals 2,056 in as many directions as possible.

From those original 13 states, the USA has grown to 50 states. To help you learn the 50 states in a fun way, explore the visual USA state mnemonics over at 50 States of Mind. They're fun, educational, and will help with the following quizzes.

The first quiz? Name all 50 states in 10 minutes, of course. If you know your states, can you name all 50 state capitals in 10 minutes?

Now that you have all that information, how well can you filter it out? One classic challenge is to name all 8 states that begin with the letter M in 1 minute. Did you find that tough? Study those states with Lou Ryder, and then go back and try again.

For a similar challenge, try and name all 21 states whose names end in the letter A in 4 minutes. No, I don't have any resources to help you learn this one.

Don't get too used to states with certain letter patterns. Geography is about physical features. Can you name the 23 states that border the Atlantic Ocean, the Pacific Ocean, or the Gulf of Mexico in 3 minutes?

I'd love to hear how well you did on any of these challenges. Let me know in the comments!

Have a safe and happy July 4th!