The concept of natural rights which was used in the Declaration of Independence was first proposed by

John Locke

Explanation:

The concept of natural rights was first proposed by an English philosopher called John Locke. He emphasized there factors known as Life, Liberty, and Property as being the core of independence and should be non-negotiable or sacrificed for anything.

This was adopted in the Declaration of Independence of the United States from Great Britain on July 4, 1776.