We hold truths self-evident: that all men are created equal, that they are endowned by their creator that gives them certian unalienable that quotations what does unalienable refer to

Normality and being sane. The opposite of unalienable would be alienable which means being an outcast or criticism for being different.
In this paragraph unalienable refers to men being equal and how this should be normality for the world.
Hope this helps if your still struggling look at BBC Bitesize

Of the revolutions of 1848.