That's my point, though. Just because we call them "inalienable" doesn't make them so, either. It's a relatively modern concept. We claim the right to Life: yet at any time the universe can throw you a curve and take you right out. Your "rights" won't make a damn bit of difference. We claim the right of Liberty: but at any time the government can whisk you away, call you a terrorist and lock you up without even a trial. So much for Liberty. We claim a right to the Pursuit of Happiness: as long as Happiness doesn't involve marrying someone of the same sex as yourself.
All of these rights, and all of those outlined in the Bill of Rights, were given to us by the founders and leaders of this country. We consider them to be inalienable, or God-given, or natural. But in actuality they are as tenuous as a wisp of smoke.