Which three Enlightenment figures influenced the writing of the Declaration of Independence?

Issued on July 4 1776, the Declaration of Independence a turning point in U.S. history which paved the way for the end of British rule. When Thomas Jefferson wrote this document, he not only used his own ideas but was strongly influenced by the following philosophers of the Enlightenment period. 

1. Dr William Small: a prominent Scottish Enlightenment figure and Jefferson's mentor. Small strongly influenced Jefferson's intellectual development and shared with him the Scottish ideals of equality and freedom 
2. John Locke: Jefferson was deeply influenced by his idea that a government should protect the rights of his citizens which Locke believed to include 'life, liberty and property.' In the Declaration, Jefferson changed these words to 'life, liberty and the pursuit of happiness.'
3. Thomas Paine: this English-born activist wrote two extremely influential pamphlets, 'The American Crisis', and 'Common Sense', which strongly inspired the independence movement. Paine called King George 'a Pharaoh' and emphasised the abuses committed by the English crown on the American people. He argued that only the solution was to declare independence and form a democratic republic.  

What Enlightenment influences impacted the American Declaration of Independence and Constitution?

The most important Enlightenment influences on these two documents were John Locke and Montesquieu, respectively.

John Locke had a tremendous influence on the ideas and words that Thomas Jefferson used in the Declaration of Independence.  He argued that government was only valid if it had the consent of the people.  He argued that its only proper purpose was to protect people’s basic rights.  These rights were, in his terms, life, liberty, and property. 

Montesquieu had an important influence on the Constitution.  His most important idea was the idea of the separation of powers.    He argued that it was important for a government’s powers to be divided between separate judicial, executive, and legislative branches. 

In these ways, the major ideas of these documents came from Locke and Montesquieu, respectively.