I thought about making this a quiz to see if anybody would be able to figure it out, but considering that I'm putting this on this late at night, I figured, I'd just spell it out.

Happy Birthday, America.

221 Years ago today (1787), the U.S. Constitution was signed and officially created the U.S.A.  

This is a day that we should celebrate in the same way that we celebrate Independence Day, however, most don't even know the significance of today.