“Serious affairs and history are carefully laid snares for the uninformed.”

Hagakure (c. 1716)

Attributed to "Addison" in A Dictionary of Thoughts : Being a Cyclopedia of Laconic Quotations from the Best Authors of the World, both Ancient and Modern (1908) edited by Tryon Edwards, p. 580, but this might be the later "Mr. Addison" who was credited with publishing Interesting Anecdotes, Memoirs, Allegories, Essays, and Poetical Fragments (1794).
Disputed

"What is War?" (1924)

Source: Ship of Destiny

US Senator William Edgar Borah, writing in The Reader's Digest, Vol. 8, Issue 2 (1929), p. 776; this has only rarely begun to be attributed to Washington, since about 2010.
Misattributed

Source: Christianity and the Social Crisis (1907), Ch.1 The Historical Roots of Christianity the Hebrew Prophets, p. 9

As quoted in No Holding Back : The 1980 John B. Anderson Presidential Campaign (2011) by Jim Mason, p. 412
Context: I had no great sense of failure. I didn’t come out of the campaign with the sense that I’d thrown my career away or thrown my life away on what was a fruitless, feckless endeavor. I felt that I had made my mark on the pages of history and laid down some markers for others possibly to follow.

Book II, Ch. 10. Of Books
Essais (1595), Bartlett's Familiar Quotations, 10th ed. (1919)

PART II, SECTION I.
An Essay on the History of Civil Society (1767)