Five and ten dollar bills. The former are or were occasionally called V spots.

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1837.  Once it [my pocket-wallet] was as portly as an alderman after the annual dinner; and when distended with V’s and X’s to its utmost capacity, it was indeed a circumstance in my pocket, worth noticing.—Knick. Mag., ix. 96 (Jan.).

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1837.  I’ll bet you a V we don’t see anything of the kind.—Balt. Comml. Transcript, May 19, p. 2/2.

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1843.  The thimble-rigger, while he pocketed the V or X of some greenhorn, did not cease to expatiate on the favorite horse.—Phila. Spirit of the Times, May 27.

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1846.  One wanted to bet him a horse on H’s colt vs. his Indian Dick—another a V., and another an X., and so on.—W. T. Porter, ed., ‘A Quarter Race in Kentucky,’ etc., p. 119.

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1848.  

        I thought thet gold-mines could be gut cheaper than Chiny asters,
An’ see myself acomin’ back like sixty Jacob Astor’s;
But sech idees soon melted down an’ did n’t leave a grease-spot;
I vow my holl sheer o’ the spiles would n’t come nigh a V spot.
Lowell, ‘Biglow Papers,’ No. 8.    

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1852.  He looked so dandified, green, and innocent, that they let him win five dollars the first time, and then, on the rigger’s proposing to bet a hundred, his supposed victim applied the finger of scorn to the nose of derision, and strutted off with his V. [note, A five-dollar bill is so called from the designation in Roman numerals upon it], to the great amusement of the bystanders.—C. A. Bristed, ‘The Upper Ten Thousand,’ p. 239 (N.Y.).

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1853.  “As I said, I’ll give you a V. for one pull.” “Say an X., and it is a bargain.”—Daily Morning Herald, St. Louis, June 28.

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1856.  

        If we had owned a V. or two,
Which vanished like the morning dew,
We wouldn’t have been surprised,—would you?
San Francisco Call, Dec. 5.    

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1857.  He insisted on spending a V. by way of a morning whet.—Id., Feb. 17.

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