Full Idea
We hold these Truths to be self-evident, that all Men are created equal, that they are endowed by their Creator with certain inalienable rights, that among these are Life, Liberty and the Pursuit of Happiness.
Gist of Idea
Men are created equal, and with certain inalienable rights
Source
Thomas Jefferson (U.S. Declaration of Independence [1775]), quoted by Johanna Oksala - Political Philosophy: all that matters Ch.4
A Reaction
In the context, saying equality and rights are 'natural' is just a way of saying we will fight to the death to defend them. The big modern problem for the U.S. is that nominal equality before the law doesn't ensure equality in society.
Book Reference
Oksala,Johanna: 'Political Philosophy' [Hodder and Stoughton 2013], p.50