Four score and seven years ago...

So begins one of the most important speeches in the history of the United States -- Abraham Lincoln's Gettysburg Address. Given on a cold November day, it wasn't much of a speech, really -- just a few remarks. Not meant to be remembered.

But these few remarks have been remembered. Why? What was the true meaning behind them? Where did they come from? Why is it so important that we never forget what President Lincoln said on that cold November day?