“I was delighted with its high tone and the flights of oratory with which it abounded, especially that concerning negro slavery, which, though I knew his Southern brethren would never suffer to pass in Congress, I certainly never would oppose”

Regarding a draft of the U.S. Declaration of Independence, Letter to Timothy Pickering (6 August 1822) http://oll.libertyfund.org/titles/2100#lf1431-02_head_061
As quoted in The Founding Fathers: John Adams: A Biography in his own Words https://web.archive.org/web/20111029143754/http://home.nas.com/lopresti/ps2.htm (1973), by James Bishop Peabody, Newsweek, New York, p. 201.
1820s
Context: A meeting we accordingly had, and conned the paper over. I was delighted with its high tone and the flights of oratory with which it abounded, especially that concerning negro slavery, which, though I knew his Southern brethren would never suffer to pass in Congress, I certainly never would oppose. There were other expressions which I would not have inserted, if I had drawn it up, particularly that which called the King tyrant. I thought this too personal; for I never believed George to be a tyrant in disposition and in nature; I always believed him to be deceived by his courtiers on both sides of the Atlantic, and in his official capacity only, cruel. I thought the expression too passionate, and too much like scolding, for so grave and solemn a document; but as Franklin and Sherman were to inspect it afterwards, I thought it would not become me to strike it out. I consented to report it, and do not now remember that I made or suggested a single alteration. We reported it to the committee of five. It was read, and I do not remember that Franklin or Sherman criticized any thing. We were all in haste. Congress was impatient, and the instrument was reported, as I believe, in Jefferson’s handwriting, as he first drew it. Congress cut off about a quarter of it, as I expected they would; but they obliterated some of the best of it, and left all that was exceptionable, if any thing in it was. I have long wondered that the original draught has not been published. I suppose the reason is, the vehement philippic against negro slavery.