A term applied to extravagant, “high-falutin” oratory.

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1858.  The sermon was a splendid failure—a much ado about nothing—and is yet laughed at as “the Spread Eagle Sermon,” as a puerile exhibition of vanity. The fewer such “swelled heads,” as they call them in Kentucky, preach in Saratoga, the better. They use the pulpit as certain vendors of quack remedies do the rocks along our railways—to advertise themselves!—Harper’s Weekly, ii. 546/4 (Aug. 28).

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1861.  A friend observed to me … that I could hardly expect, under the [present] circumstances, to regale my auditors with the usual amount of spread-eagleism.—Henry James, 4th of July oration at Newport, R.I.

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