“The captain-general’s ship flew at its mast a flag on which was painted a large cross of Christ and also carried cannon, symbols of the new power entering the East.”

quote from 1988
1981 - 1990
Source: Tàpies, Werke auf Papier 1943 – 2003, Achim Sommer, Kunsthalle Emden, Altana 2004, p. 27

Many variants of this exist, but the earliest known incident of such a comment appears to be a partial quote from James Waterman Wise, Jr., reported in a 1936 issue of The Christian Century: "in a recent address here before the liberal John Reed club [Wise] said that Hearst and Coughlin are the two chief exponents of fascism in America. If fascism comes, he added, it will not be identified with any 'shirt' movement, nor with an 'insignia,' but it will probably be 'wrapped up in the American flag and heralded as a plea for liberty and preservation of the constitution.'"
Another early quote is that of Halford E. Luccock, in Keeping Life Out of Confusion (1938): "When and if fascism comes to America it will not be labeled 'made in Germany'; it will not be marked with a swastika; it will not even be called fascism; it will be called, of course, 'Americanism.'" (This quote is also attributed in a New York Times article from September 12, 1938, page 15 as having been given in one of Luccock's sermons.)
Harrison Evans Salisbury in 1971 remarked about Lewis: "Sinclair Lewis aptly predicted in It Can't Happen Here that if fascism came to America it would come wrapped in the flag and whistling 'The Star Spangled Banner.'"
Source: The Christian Century, Volume 53, Feb 5, 1936, p. 245
Source: Misattributed, p. 29, The Many Americas Shall Be One, Harrison Evans Salisbury. Published by W. W. Norton, 1971.

A children's folk rhyme quoted in the front pages of the book.
One Flew Over the Cuckoo's Nest (1962)

By the Waters of Babylon (1937)
Context: I went fasting, as is the law. My body hurt but not my heart. When the dawn came, I was out of sight of the village. I prayed and purified myself, waiting for a sign. The sign was an eagle. It flew east.
Sometimes signs are sent by bad spirits. I waited again on the flat rock, fasting, taking no food. I was very still — I could feel the sky above me and the earth beneath. I waited till the sun was beginning to sink. Then three deer passed in the valley going east — they did not mind me or see me. There was a white fawn with them — a very great sign.

Source: Tropic of Cancer

Aburish, Said K. (2004), Nasser, the Last Arab, New York City

Source: Kilroy Was Here (1996), p. 152

From the sermon "Glorying in the Cross", published in 1768. Misquoted since 1845 as "Cursed be all that learning that is contrary to the cross of Christ; cursed be all that learning that is not coincident with the cross of Christ; cursed be all that learning that is not subservient to the cross of Christ." So quoted by S. S. Cox in October 1845, in Permanent Documents of the Society for the Promotion of Collegiate and Theological Education at the West, Volume 1, p. 30.

Li rois d'Engleterre et li sien, qui s'en venoient tout singlant, regardent et voient devers l'Escluse si grant quantité de vaissiaus que des mas ce sambloient droitement uns bos.
Book 1, p. 62.
Chroniques (1369–1400)