Thank you to everyone who took the time to make a suggestion. I will save this link and use it to find more books to read.
By coincidence I am currently also read a book about U.S. history, "The Vineyard of Liberty" by James MacGregor Burns, and on Page 170 there's a description of dinner at the White House: "Mr. Jefferson said that the Epicurean philosophy came nearest to the truth, in his opinion, of any ancient system of philosophy, but that it had been misnunderstood and misrepresented. He wished he work of Gassendi concerning it had been translated ... I mentioned Lucretius. He said that was only a part -- only the natural philosophy. But the moral philosophy was only to be found in Gassendi." (That's John Quincy Adams who is being quoted).
I am sorry I have not checked in very much at this Forum, but I intend to be better about that.