Brief Summary
The Set-Up
France was blowing up, the revolution was underway, and it was time to figure out what people wanted to get out of it. Nothing makes a revolution legit like a good declaration of rights.
The Text
The National Assembly took a bold step and declared that all of France's problems are the result of its shady government. But never fear, because they've also taken the liberty of listing the rights that the government should be recognizing as well as defining a few key terms that the current French leader (ahem, the king) don't seem to understand.
They list seventeen articles that contain such gems as asserting that all men are created equal and have a right to free speech, religion, and a representative government that will decide on taxes and laws. Just so as there's no confusion, they explain what they mean by sovereignty, liberty, law and other tricky legal terms that Louis or his advisors might try to finagle later.
TL;DR
The royal family has sunk France neck-deep in an unfortunate mess, so it's time to spell things out for them: people have rights that even you have to respect.