Loved your point about "inalienable rights"... First of all, they're not "inalienable". People can easily find themselves living as slaves, virtually overnight.
Inalienable and violated are different things. Inalienable means that my moral right can't be taken away, not that it can't be violated. It means that those slaves have a moral right to rebel, to fight back, and that those who have enslaved them are in the wrong.
...when something is an "inalienable right", why celebrate it? Do we celebrate "Gravity Day" every year? Gravity is constant, and humans depend upon it... we know it to be inalienable, and therefore we regard it by now as our right. Of course not. You celebrate that which you know damn well is wonderful but tenuous!
We celebrate the birth of a government that is based upon those inalienable rights. We celebrate the idea of a government whose purpose is the protection of those rights.