Here's an interesting article tracing Epicurean ideas from Epicurus to Jefferson through several French philosophers including Rousseau (who I have certainly heard of but am not very familiar with) and Burlamaqui (who I am not sure I have ever heard of before). Other than some discussion about Gassendi I don't think we have developed in the past to what extent these influential French thinkers embraced and accepted or deviated from Epicurus, or what they thought of Epicurus at all. Apparently this Burlamaqui was particularly influential in some of his phrasing, and might be the place Jefferson picked up "Pursuit of Happiness" as a phrase. I've only started to read the article but if anyone (particularly Charles) has insights into this I would like to begin to get a fix on whether we should consider some of these prominent Frenchmen to be pro-Epicurean or outside of the main line of Epicurean thought.
https://www.sociostudies.org/journal/files/seh/2013_2/156-182.pdf
Couple of interesting comments:
All the references showing Jefferson's interest in Epicurus' philosophy known to me date back exclusively to this much later period in his life. This makes it unlikely, but not entirely impossible, that Epicurus' philosophy played a major direct role in Jefferson's thinking in July of 1776.
Also, sounds like D'Holbach's "System of Nature" is important for its anti-religious nature. Another German, Martin....
Looks like we may eventually need a separate thread on D'Holbach, especially if we can find him directly commenting on Epicurus.
Well this "System of Nature" certainly seems important. We'll need a link to an English translation....
A questionable paragraph!
Translation: http://www.ftarchives.net/holbach/system/0syscontents.htm
We also need "Christianity Unveiled' also by D'Holbach. Another reason for Martin to look further in D'Holbach! 
